If you just want a starter field camera, then I'm not sure a new camera is the best thing to do, especially if you are on a budget. I suggest reading everything at http://www.largeformatphotography.info/ and possibly getting a graflex or something similar. For example, I have a Meridian 45B with just about all of the movements that you would ever need (and more). It doesn't have a removable groundglass, but I haven't found a need for that yet.

Once you really get comfortable with the 4x5 then you will be ready to buy a new 8x10 :-)

For lenses, see http://www.hevanet.com/cperez/kit.html for a good rundown of inexpensive (and some not so) lenses.

I also have to mention that the best way to do large format for cheap is an old Polaroid 100 or 101 and a pack of 665. $15 on Ebay. See http://www.rwhirled.com/landlist/landhome.htm

If you aren't concerned about the cost, then there are a lot of great cameras available new, but it adds up quick.