I also use a P509 and have tried many Cm7 roms. You will not find a better rom than Gingersnap from the previous poster. I can't believe how well my device operates.
As far as rooting and recovery, a quick youtube search will give you many nice video tutorials. I hesitated for a long time before rooting but the youtube videos made it look so easy, which it is.
Sent from my LG-P500 using xda app-developers app
---------- Post added at 03:06 AM ---------- Previous post was at 02:55 AM ----------
To root: watch youtube video "How to root LG Optimus T" by click4geeks. Use Gingerbreak if you have 2.2.2.
Recovery: use Rom Manager from Market to install CWM.
Sent from my LG-P500 using xda app-developers app