Bicycle Mechanics - Novice needs bike part help (pedal Giant iguana)

Hi,
I dont know much about bikes or how to fix them, but I am handy enough to do self repairs.
I have a Giant Iguana 650 mountain bike. The left pedal fell off (non gear side) due to a loose bolt/nut (which was lost but have the crank arm+pedal). I have no idea what this nut/part would be called and if it's some common universal size or not.

Can anyone recommend a good, low priced online bike part retailer, and what part and possibly tools I need? I assume I can just get the part put the pedal back on and tighten the nut or whatever.

Also the bike has been sitting for over 2 years. Anything I should do like lubrication, check brake pads (I bought new tires recently)? Can anyone recommend a good chain lock too, lighter the better but still not easily cuttable.

Thanks for your help!

So there is no threads attached to the pedal? if there is, that means you just need to screw the pedal in using a pedal wrench. Remember, the left pedal is reverse threaded. As for cheap tools, try nashbar.com or pricepoint.com. Since you dont know much about bike maintenance i would suggest you take it into a bike shop for a tune up. or purchase a book on bike mechanics. Park Tool makes an excellent repair book.

Thanks MattP. I was doing a little more investigating and I think I need a crank nut? Basically I have a crank and pedal not attached to the square bolt coming out of the bottom bracket. The threads all look fine and not stripped. So I will need a replacement crank nut to reattach the crank then I think there is a cap that goes over that? I can't seem to find the parts though. I'd like to take the bike to a shop but its inconvenient where I am.

Crank bolts. http://www.jensonusa.com/store/product/CR707Z00-Capless+Crank+Bolts.aspx

Your local shop should have one. If you've got a place that sells used stuff, that's the first place to try.

I would examine your square tapers for damage also. Riding with a loose crank arm can't be good for it, especially to the point where it came clear off.

Cheers

thanks Eros, that's what I need. The square tapers look good so do the threads. When I put the crank on it does not feel loose, there is no side to side shimmying. I'll give this a shot and if it's loose and it looks like I'll have to take it to a bike shop and get a new bottom bracket installed. (reason I haven't taken it to a shop is because its 2 mile walking the bike, just thought maybe I could order a part and be done with it)

I just need this bike for light use for the rest of the year then I am going to get a new one.