Look before you turn. Pausing to examine the order pieces come apart or how a part attaches can make putting the bike back together much easier.
Nothing is worse than putting a hub or bottom bracket back together minus one ball bearing.
If you're stuck, and you will be at times, often your best source of information is just down the street at the local bike shop. That alone can make the job a helluva lot easier. Don't pay those inflated repair costs when a little common sense and the right tool will get you through. A basic bike repair and maintenance manual, new or used, is a good reference to have on your shelf. The nice thing about a home shop is that you can do trial runs.