Essential Apps for new Droid User...
I too am new to the world of droids (well read regarding symbian hacks/mods). I am also a very quick learner. In the short time I have owned my Flipout (UK), I have learned that there are a few apps that are essential installations for rooted users.
1: "Titanium Backup" (paid if possible)...essential for nand backup (rom)..system backup, App installation & a whole host of other needed routines.
2: "BusyBox" standalone installation or install from within "Titanium Backup"
3: latest "Clockwork" recovery tools (search on here for more info on this).
4: Setcpu..? (no kernal modded for overclocking is available yet for the flipout so this fact alone makes installation of Setcpu questionable unless you want to underclock to save battery?).
5: Root Explorer..(very usefull for locating those elusive system files that we sometimes need to edit).
6: RSDlite..Stable, reliable & essential for full firmware rom flashing.
7: UniversalAndroot..(for future rooting projects)(renowned for stability & user friendliness).
I would consider all the above Apps to be essential as most of what you are gonna want to do on or with your Flipout will require the phone to be rooted & at least 1 or more of the listed Apps to be installed.
There is a whole world of Droid Apps at your disposal (Market & other sources) once your rooted & set up but we'll leave the fun of discovering some of them to you.
Hope this post has been of some help to you...
Stay Breezy & Be Lucky...