As stated, TuTu is really a must. I haven't played the Trilogy pack so can't speak to that, but TuTu allows you not only to play on a superiour graphics engine, it also allows you to play with all of the classes in BG2.
Also look for "Unfinished Business" mod. it rounds out quite a lot of the stuff that was either broken or just plain not finished.
Another thing. Make sure that you play the heck out of BG1 and then carry your character over to BG2. that way you can make use of the extra EXP and all of the tomes that are scattered around BG1.
And do some research on some of the things you can carry over from one game to the next. There are several artifacts that you find in BG1 that are actually quite useful well into BG2.
Finally, make sure that ToB is installed and go into the "Extra" castle as soon as you are able. Even if you can't make it very far, they have unlimited arrows and bolts packs for sale and to be found in the early levels. Of course play all the way down to the secret toy surprise at the bottom, but you may have to hold that off till later. The initial foray is really worth it early though.