I highly reccomend that you get a book called "Practical Fishing Knots" by Lefty Kreh and Mark Sosin. It has just about every knot you can imagine for all types of fishing. I believe it is only about $15 so not a bad investment. Most fly shops have it. I would think if you bought the outfit from a shop they will help you out. Some might even in the hope of getting your future business. If thats not possible try finding the following on the internet.
Arbor Knot for backing to reel.
Surgeon's Loop to create a loop in the backing
Double Nail Knot loop in the back of the fly line
Nail Knot for fly line to leader
Clinch knot for leader to fly
Hope that helps.