What mods would be good to use with BG 1&2?

Honestly, it depends what you're after. There's a fix pack if you want a more by-the-books experience (I actually prefer not to use it because I actually like the fact that certain spells stack), as well as a tweak pack if you'd rather change the rules. If it's your first time playing, you might want to be careful how much you mod. In particular, I would avoid mods that add new content.

Two of the more interesting mods out there are Tutu and Trilogy. With one of those mods, you can play BG1 using BG2's engine. Be aware that some of the BG2 classes might not be balanced in BG1, so be careful.

As for the mods I would personally use, I would get rid of resting limitations (I dislike not being able to rest outside in town) and restore the BG1 weapon proficiency system (but still allow combat styles). Most modders like the fix pack, but I don't because it has fixes I don't like (like preventing stacking) and isn't modular (so you can't just choose the fixes you want).

I played BG 1&2 when they first came out and want to experience both games as one. I've read about a mod that puts stuff back in the game that were cut out and one called widescreen. Any recommendation as to what is a have to be?

I've never used mods so any help would be greatly appreciate it.

I tried installing mods but all it did was make the game not play so, I guess, I'll stick to the way the games are.