iCloud is part of 10.7 Lion while you're running 10.5 Leopard. First you'll need to upgrade to 10.6 Snow Leoprad.
The 10.6 Snow Leopard DVD is back in the Apple online store. You can now get it for $19.99 without having to phone the store. http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard The App Store which is required to download 10.7 Lion or 10.8 Mountain Lion is part of the 10.6.6 update.
Any program that runs under 10.5 should run under10.6. See this list for compatibility with 10.6: http://snowleopard.wikidot.com/ You might have to upgrade some drivers for printers, etc.... And you will have to install Rosetta if you have any Power PC applications http://www.macobserver.com/tmo/article/snow_leopard_installing_rosetta/
Once you are at 10.6.8 Lion is still available from Apple through the App Store. You will have to call Apple Customer Care 1-800-692-7753 or 1-800-676-2775. to purchase it. Then within 3 days you will get an email with a code which you can use to download Lion from the App Store. The price is $19.99.
You must have at least a model 2,1 MacBook. Lion will require at least 2gb of RAM but really needs 4gb to run smoothly.
As for third party programs see this list for compatibility with 10.7 http://roaringapps.com/apps:table
Also Lion doesn't run any Power PC programs. To see if you have any Power PC programs go to the Apple in the upper left corner and select About This Mac, then click on More Info. When System Profiler comes up select Applications under Software. Then look under Kind to see if any of your applications are listed as Power PC. Universal and Intel will run under Lion.
Before Mac switched to Intel processors in 2006 they used Power PC processors from 1994 to 2005. Power PC 601 through 604, G3, G4 and G5. Applications written for the Power PC processors need the application called Rosetta to run on Intel processors. This was part of the Operating System in 10.4 and 10.5 but was an optional install in 10.6. With 10.7 Lion Apple dropped all support for Power PC applications.
I have this issue as well and I have already upgraded to Snow Leopard after upgrading to Leopard first. When I go to the icloud site it says I need at least 10.7 to sync my mail. Problem is that I have a me account and that site is closed when I attempt to access it on my Macs, or my PCs? My settings are no longer staying either on the Apple sites, or on my Preferences. me.com is the only option left on my Preference Tabs and unable to add Mail option back? What could be going on here? I have a Macbook running 10.68 with 1.83 GHz on Intel with 2GB 667 MHz DDR. Even My Stuff, listed on this site appears to be erased, along with my History here.
Oh forgot to note that 10.68 is the highest upgrade possible on this Macbook so how do I sync my mail or even access it on my PCs. My IMac is locked up with an unknown Firmware password and the local Apple Store is unable to reset it as was the Apple Tech Department that handles this through Apple Care. The local contact I was referred to is no longer local and over 1.75 hrs drive one way. I'm locked out of my mail and unable to fix any of these strange issues I keep having lately. SOS!
Message was edited by: suzieseller
While we all have MacBooks in this forum most of us don’t use iCloud. There's an iCloud Support Community where everybody uses iCloud. You should also post this question there to increase your chances of getting an answer. https://discussions.apple.com/community/icloud/icloud_on_my_mac