The best thing to do after rooting is choosing a ROM and loading it. I think the world of Apex 1.4 and the last Liberty 1.5 was pretty good too. Both of these ROMs have most if not all the BLUR garbage removed yet allow you to replace the BLUR components you enjoyed/used prior to loading a ROM.
Having root also lets you do stuff like taking screen shots when you want to show something, wireless tether, access all the files on your phone not just those on the SD card....
The most important thing is that you do your due diligence and read and understand what you are doing BEFORE you do it. Learning to make a backup before you make a major change, follow the installation directions to the letter and ASK when you just dont know. Im by no means a pro at any of this, to most im an old man walking in a new age world and reading and understanding and asking when I dont has kept me from having "issues".