Need some advice

Good evening everyone. OK, I just reinstalled FSX and SP1. As a polished FS9 user, I am soooooo out of the loop here with FSX and need some help.I am just plain frustrated because I neglected to stay in the loop since FSX was released, and have been on the FS9 side of the forums. I have no idea what I should be setting up the sim to run as smooth as possible and correctly. For example, should I set my AA and AF outside of the sim and in, or just one or the other. Also, I saw something mentioned about additional tweaks that may help for dual cores etc..., but now they seem to be gone from Phils blog. I hate to sound like such an idiot, but this is really the first time I have set up FSX with the intention to actually use it now that SP1 is here, and as all of you already know, it is a totally different animal. Any help is most appreciated. I was running at KSEA in the CRJ700 with not that great performance,(15-25/locked at 28 alot of stuttering) especially after takeoff heading north, but I know it's due to my settings. Thanks again for anyone kind enough to get me headed in the right direction. I will crawl back under my rock now as this is quite embarrassing for me that I actually have no idea what I'm doing. :(