Alright, I've relaxed, had a beer, and KU is whoopin' up on Missouri. So now I have the energy to ramble on and on about LF.
Is it a big, heavy, metal camera? Then it's probably one of the many variations (by many manufacturers) of a 5x7 Graphic View. you can get info on these from
www.graflex.org click on "other cameras" or something like that (the site is mostly about 4x5 Speed Graphic press cameras).
Does it have a lens with it? I can't remember exactly what the "normal" focal length for 5x7 is, but it's got to be about 210mm. 150mm is normal for 4x5. When buying lenses try to get ones that cover 5x7, and you'll be able to use them with either film size. There are a lot of cheaper, but still pretty nice, press lenses available that will cover 4x5, but not 5x7. I use a Schneider 150/265mm convertable lens; remove one element and it goes from 150mm to 265mm. It's a little soft compared to many large format lenses; it's still an awesome lens. I don't know if it would cover 5x7, but it would be sort of a good 2 in 1 lens if it did. Normal and a little tele for 4x5, and wide and just over normal for 5x7.
Besides film and a lens in a shutter on a lens board you will need(*means it's a must):
*tripod
*cable release
*film holders (hold two sheets each, some 4x5 holders hold 5 or 6)
meter (you can use a camera with a meter)
*darkcloth (lots of DIY possibilities here)
notebook (take notes!!!)
film changing bag (for changing film in the field if you don't have enough holders, or no darkroom to load film)
*light tight box (to put exposed film in; old film box works best, but you could use the bag out of a box of photo paper)
backpack(if you're going to haul this anywhere)
filters?
lens hood (always)
polaroid back (if you are using E6 or paying for processing)
polaroid sheet film