gmail and google calendar will both sync to the iPhone with no problem. Just go to settings->Mail->Add account, add your gmail account and it will give you the option of syncing calendars as well. For some odd reason, you have to separately sync contacts:
There's a free google map app that's vastly superior to the (still laughably bad) Apple Maps app. The only problem is that you can't set it as the default map app. That is, when you click an address on a web page or in email, it will open the Apple Map App. No way to change that without jailbreaking. You have to cut and paste to use Google Maps.
OH DEAR, this is a major complaint I had with the ANDROID when I firs got it: It synced ALL my Google contacts at the time-ALL 3500 of them.
If i do my homework ahead of time, is there a way to some how sync a subset of contacts?
can I do this somehow manually on my computer and check the contacts I want to transfer instead of ALL of them all at once?
For that matter, is there a systematically a way to , in an orderly fashion, transfer a years worth of accumlated stuff to my new Iphone-5?