I'm going to pick them up in about an hour!
What site do I go to in order to download patches? Are there any unofficial/community patches and/or content? I'm running Windows XP 64-bit, do I need a patch?
BG worked perfectly fine for me on Windows 7 64-bit, so I don't imagine you'll have much trouble with XP.
Also, allow me to second, third, and fourth povuloho's recommendation for Tutu. I used a slightly more simplified version of it, myself (easyTutu), but I'd recommend either--especially since a lot of BG mods these days simply assume you're running the first game through a version of Tutu. http://forums.gibberlings3.net/index.php?showtopic=8122 has a good guide for what to install when where Tutu and other mods are concerned. Also, I recommend the http://www.gibberlings3.net/bg1npc/--it adds a number of BG2 style banters and occasional sidequests, which are otherwise lacking for BG1. They're all very well written in regards to keeping things in-character and in-lore, and some of the interactions between party members are absolutely priceless.
I'm trying to remember what mods I had for BG2...I think I kept it pretty vanilla, with just the Baldurdash fixpacks and http://www.pocketplane.net/mambo/index.php?option=com_content&task=blogcategory&id=101&Itemid=80 (adds some cut content back into the game).
the game makes you fight against high level assassins basically forcing you to use a ranged weapon character.
BG1 is not Oblivion--it's not even Morrowind. There is no level-scaling, and it is not interested in coddling you. You will probably struggle in the early portions of the game. It is, however, entirely possible to play the game with a spellcaster character (been there, done that, t-shirt purchased), or a melee fighter...just a matter of getting the right party together and figuring out what works for you. Personally, I find winning a fight against assassins ten or twelve levels higher than me in BG1 to be far more rewarding than an evenly matched (level-wise) fight in Oblivion.
As for characters you find annoying...that's the beauty of Baldur's Gate: there's enough NPC variety to pick whatever party you want. You aren't married to Imoen and Minsc (that'd be the guy with the hamster--true, he's the best tank in the entire game in addition to being comedy gold, but there
are other tank characters). If you find them all annoying, well--that's your problem, then.