How to make your own bicycle repairs is a very broad subject.
It can cover every thing from fixing a flat to over-hauling your entire bicycle.
To be successful at any repair it is always important to have the correct tools.
Having the correct tools can take a lot of the frustration out of the repair.
There are a variety of repairs that can be made on a bicycle with limited experience. This is a list of topics that will be covered.
Flat tire repair Bearing replacement Truing a wheel Changing a chain Changing a pedal
Or you can get a repair manual and learn how to do it yourself.
The first two categories will be discussed in further detail on their own pages. I will not be discussing them here.
Your first step in truing a wheel is to get a wheel truer. This is an apparatus that can hold your wheel.
It comes with a little gauge you place up against the wheel.
The process of truing a wheel takes practice to get correct.
You place the gauge next to the rim, zero it out, and spin the wheel.
The amount the wheel moves the gauge, either + or -, is how much the rim is out of true.
The way to get it back into true. Is done by tightening or loosening the spoke opposite of where bend is at.
Do not expect to get the wheel true your first time attempting.
Changing a chain is straight forward and easy if you have a chain removal tool.
Get yourself a chain removal tool from a bike shop or maybe a place like Wal-Mart.
Remove one of the pins, pull the chain through the derailleurs. Do the reverse with the new chain.
Changing a pedal is fairly easy too. Get the appropriate wrenches or a pedal wrench. The tricky part of doing a pedal change is keeping the pedal from moving.
To accomplish this, have someone hold the bike or use a bike stand. Put the pedal parallel to the seat post tube, in the down position. Do a quick jerk of the wrench. This usually releases the pedal.
Remember pedal threads are opposite, left handed, from most threads.
These are some of the make your own bicycle repairs you can do yourself. Check back often for addition repairs you can do or just subscribe to the rss feed on the side. It will keep you up to date.
The process of truing a wheel takes practice to get correct. 
