I do 3 sets, first set of 15, then 12, then 8. i guess i dont go 100% on the first 2 sets cuz i try to save energy for the last one, is that a good technique? and btw this is gonna sound retarded but..when you say how much you bench, you include the weight of the barbell right?

Haha yes you include the bar (which is usually 40 or 45 lbs)
I have always been into working out but just got into weightlifting....btw i weigh 148 and bench 225....here are just some basic tips.
-Always have a spotter
-Stretch out and warm up beforehand
-Make sure when you are weight lifting you are not just benching, but working all major muscle groups to get a full workout
-Lift everyother day to give your muscles time to recover
-In bench make sure you keep the bar steady and when you bring the bar down your hands should be wide enough so your elbows make 90 degree angles
-Plant your feet to give yourself a good base
-Inhale when bringing the bar down, exhale when pressing up
Thats about it man, if you have any other questions just shooot

and and btw when i do sets i alternate between a pyramid and drop sets, so say on monday i'll do drop sets( start at max weight you can do 10 reps of and then drop 5 lbs and do 10 reps, repeated till your down to the bar) to work my endurance, and then wednesday ill do a pyramid work out(start at max ten rep and then at 5 lbs and drop 2 reps and then do that until your at 2 reps and you're up 20 lbs from your starting weight, then you go back down, decreasing weight, adding rep until your back to your starting set), and then on friday i'll do drop-sets again
hope this helps