Rooted... now what

Hey everybody.  So I rooted by phone following the instructions from theunlockr.com at this site:

http://theunlockr.com/2010/08/02/how-to-root-the-samsung-vibrant-Captivate/

and then followed these instructions:

http://theunlockr.com/2010/08/02/how-to-load-a-custom-rom-on-the-samsung-Captivate-vibrant/

Now what exactly do I do?  I mean I kind of understand ROMs but if I want to install 2.2 what should I do?  Is Cognition a good choice?  How exactly would I install that?  Also if I install 2.2 would I be able to go back to 2.1 when the official is finally released?  I understand enough to mod my phone but not fully enough how to change it back if I mess up.  So could I please get some help?

Also:
- What new things can I actually do w/ 2.2?
- Will I have to reinstall all my apps? Contacts?

Thanks in advance!

Thanks!  I took the plunge and installed cognition.  Is cognition exactly the same as 2.2?  Is there any way to get the Samsung keyboard back?  Because now I only have Swype and the Android keyboards.

Thanks

P.S.  What exactly is ODIN?  I hear a lot about it but I can't find exactly what it is.  Someone told me to xda-developers that there is a 3-step restore using ODIN.
And how to I apply the proprietary 1 point lagfix?  I ran Quandrant and with Cognition on there I got 1483 but I saw with the lagfix it can get into the 1800 and 1900s