You need to know the number of cogs on the rear cassette. You'll ask for an 8-speed chain, a 9-speed chain, or a 10-speed chain. You need a chain tool to cut the new chain to the same length as the old one. SRAM chains are easy to install, as they have a powerlink that slides together to connect the chain. Shimano chains must be put together with a chain tool and a special pin, and the procedure is quite specific. Just read the directions that come with the chain.
Oil is good, grease is better.
2007 Peter Mooney w/S&S couplers/Terry Butterfly
1993 Bridgestone MB-3/Avocet O2 Air 40W
1980 Columbus Frame with 1970 Campy parts
1954 Raleigh 3-speed/Brooks B72