EF 50mm - either the f/1.8, or if you can afford it, the f/1.4 (about 5-6 times the price)

2lenses: anything that gives you a 28-105mm. This allows you to do tables and other wide shots and moving ib close will give your viewer the sense of being there. The long end will mork for formals and aisle shots.
AND,something in the 100-300 range will allow you some latitude with your formals and get the shots from the balcony.
Don't forget you have a 1.6 factor with the Canon!

The Canon 85MM 1.8 has been THE best lens for the Money! Take my word for it!. I've used the 50mm 1.8 for years only to "upgrade" to this one and be knocked off my socks. I payed $330 at Adorama.

I have been taking pictures for about a year and a half now. I started with sports photgraphy and have done some portraits. I recently had my first wedding. The lighting in the building was horrible. I have a Canon 20D and used my 18-55mm, 1:3.5 - 5.6 II lens. Was this a bad choice? I also have 75 - 300mm 4-5.6 Zoom lens and 10-22mm 3.5-4.5 wide angle zoom. Do you have any suggestions on another type of lens that might work for wedding photography. I have taken a few courses but still do not fully understand the lens stuff.

I'm with Ronk. I used a 28-105 zoom lens on my Pentax PZ20 in the 90's, and used to use a fixed 105 on my old Nikon F in the mid/late 70's. I'd have to say that I personally believe that 85mm to 105mm is perfect for portraiture work.

I just read a review here about a new Canon 85mm Portrait Lens, but if the quoted MSRP was right ($2000.00), all I can say is ... Youch!

One of the best books on the basics is Kodak's "Joy of Photography", Photosinmotion. The various focal lengths and their relationship to aperture and distance are demonstrated effectively.