Really lost on installing Mavericks...any help?

I do use Time Machine for backups and have backed up my partitions. I do know how to change my desktop pictures in system preferences, but what I was asking is how to delete a desktop picture I added at one time and no longer want it. In Snow Leopard I go to the Library and Desktop Pictures and can delete the picture there, but can't seem to do this in Mavericks???

I am open to leaving both partitions. I just don't want to have to go back and forth between them so often. I would like to start using Mavericks exclusively but don't want Mail coming into both partitions, etc. so would basically like to migrate or set-up (not sure which one I would do since it is "1" Mac and just want to transfer files from one partition to the other. But I want to be sure all my mail and saved emails, files, etc., are all transferred from one partition to the other. Once done then I will use Mavericks all the time, but leave Snow Leopard there for any issues with programs, etc. I assume I can migrate my mail to the new mail in Mavericks with all my old emails, etc., and then remove access in Snow Leopard to mail so I no longer get mail there?

OK, can I do this following the instructions under Migratiting using Time Machine or other transfer migrations...just transfer everything from Snow Leopard to Mavericks? If I just go into Mavericks and copy the files, I don't think that will copy my old emails and all will it? I can do the pictures that way, but I want all my applications (mainly Quark) and all my favorites, bookmarks and all to be transferred as well and just copying from within Maverick to Snow Leopard I don't think will also copy the preferences, etc, will it? Also, to alleviate problems, would it be best if I go into Disk Utility and completely erase the Maverick partition and install it brand new? It is free to upgrade so not sure if I can install Mavericks from scratch for free??? Or would I have to install Snow Leopard again, then upgrade to Mavericks, then can I do a migrate from Snow Leopard partition to the new Mavericks partition? To me it sounds like doing a complete migrate will copy all files including my old emails, etc., right?

I did find the library (not sure why it's hidden now and wasn't in SnowLeopard) but I find no desktop pictures folder anywhere. I just have one annoying picture I once put in Mavericks and like to do the auto rotate of pictures and that one picture I want to be rid of. There has to be somewhere that these pictures are located on the partition? Maybe if I can do per above, a brand new install of Mavericks (if that can be done for free per above) that would remove that picture, was probably transferred over when I did Lion previously...

OK, I got brave and tried to migrate today. I went thru the Migration option while signed into Maverick and selected to migrate Snow Leopard to my Mac when signed into Mavericks. It appears all applications moved over, but none of my Safari bookmarks or favorites transferred over and I thought all of that would transfer also? Also, mail only pulled 392 files from 6/7 forward I presume from my Verizon file, but never transferred over any of my saved emails (which I have many and need transferred), or anything in my current mailbox I have saved - like payments I need to make, etc.. How do all my favorites, bookmarks, and mail get transferred over? Also, it asked if I wanted to rename my users folder and I selected to not rename it but move it into a disconnected folder. But I don't have any files, which are all my pictures, Quark files I've made, documents, etc., and need those as well. When I go into Snow Leopard, I can select Mavericks and under Mavericks it has 2 user folders, gsnicker which is my Mavericks user that has basically nothing I have because haven't saved anything in Mavericks, but it also shows garyschnetter, which is my Snow Leopard folder with all this info. It also shows a disconnected folder with all the files also. Why does it show in Snow Leopard under Mavericks, but not in Mavericks. Or am I just not finding it because this is so much different. Snow Leopard actually had desktop icons to see everything and with Mavericks I have to click on the finder icon and it doesn't show there. Also none of my address book entries came over. When I try to see if I can import them thru address book, which I assume they are in my Users Library, it has a red circle with a minus so can't go into the folder. Appreciate your help so much! Am sure will have many more questions but hopefully these are the main ones.

OK, since you said I didn't migrate the user folder, I thought I can just migrate that. So I went to migrate manager in Mavericks and unchecked all except the user folder, selected the option to rename it and took another hour to migrate. Still don't see it in Mavericks. When I do my restart, I see 2 systems, Snow Leopard and Mavericks. When I select Mavericks to go into it comes up with 3 options, Snow Leopard, Mavericks Partition 2, or GJFS (which is what I renamed the user folder to). When I go into Snow Leopard I can highlight Mavericks and it shows 3 users - garyschnetter (Snow Leopard), gsnicker (Mavericks), and GJFS (the new one), all under Users, but in Mavericks it only shows garyschnetter (Snow Leopard) and gsnicker (Mavericks). Why do I see it in Snow Leopard as active with no red dots but in Mavericks it doesn't show up? If I select GJFS (the new user folder I migrated) when all 3 come up (Snow Leopard, Mavericks Partition 2, GFJS) it takes me to some cloud option where I have to sign in with Apple ID. What did I do wrong? I just need to migrate my Snow Leopard User Folder so it is active in Mavericks and all my settings, emails, favorites, addresses, pictures, files, etc., transfer to Mavericks. I haven't tried what you mentioned in the last email yet because that sounds like only one file coming over and I need all my user folder transfered over. I don't understand why if I only migrated the user folder (like I did previously when I transferred everything else and that worked) why the user folder isn't in Mavericks now, at least not under finder gsnicker...where would it be? In Snow Leopard when I highlight "Mavericks partition" it shows 3 user folders (gsnicker which is Mavericks with nothing much except the basic; garyschnetter which is the one I want which is my snow leopard user with all the info, and GJFS which looks useable and same as snow leopard folder), but in Mavericks I only show garyschnetter with the red dots and minus sign that won't let me use it, and gsnicker which is the Mavericks basic stuff. Can't I just migrate the user folder by only selecting that? Can I do it from the backup? Can you give me complete instructions? Thanks so much, so confused.

I thought I did. When migrating it said work needed to be done on the users folders - Gave me the option to "replace" on this Mac, which I selected, or keep both user accounts and change the name. I selected replace thinking it would just replace the users folder on the Mavericks partition with the snow leopard partition, but apparently none of it migrated. Now in Snow Leopard it shows GJFS is on Mavericks, but it is not in Mavericks that I can see, only show gsnicker in Mavericks which has just the installed options and nothing from Snow Leopard I need. I tried to just migrate it changing the name to GJFS, which seems to have put another icloud thing under GJFS because I select to startup with Mavericks and only shows 2 partitions, snowleopard and mavericks, but once I get into it there are 3, snow leopard, mavericks and GJFS, which I thought I was migrating to Mavericks. How can I get rid of that third (not really a partition because isn't under start-up disk but shows as something to select and sign into once I restart??? I just need to migrate my snow leopard user folder (garyschnetter) to Mavericks (gsnicker). Don't need anything in the Mavericks one. How do I get rid of GJFS now and get my user fold to Mavericks...tried both migration options and neither put it there. In Mavericks only shows gsnicker and in the Snow Leopard folder I can see alll 3 user folders, but can't use them in Mavericks??? Also, now in Mavericks everything seems to be super slow...always waiting. Grab a window and have to keep regrabbing it and scrolling bar keeps losing grip and have to regrip...

Here is what it shows in Snow Leopard: