I got my Q9650, ASUS P5P43TD up to 3.76 with 8gb DDR 1333. Could probably push it higher but it's nice and stable at 3.76 with no heat issues. With these boards a lot depends on the quality of the memory. Took me a while to figure it out as I'm a novice to OC also.
I watched these vids that provided a lot of help. This one is the closest to my BIOS settings:
View: https://www.youtube.com/watch?v=t7yO79jw2OA
Search YouTube for more: "overclock q9650 asus P5p" for more.
Make changes incrementally, one at a time, preferably or you won't know which change did what. Don't make big or lots of changes in one step. Generally have to step up memory and CPU (Vcore) voltage but do it minimally or you can fry them.
Also, download SpeedFan
https://www.almico.com/sfdownload.php or some other temperature monitoring program to keep an eye on your temps.
Watch for memory instability like crashes, freezing, random program shutdowns, etc. If it's really bad, it won't boot at all.
Good luck.