Purses and bags are generally pretty simple to make, but the details and instructions can be confusing to some. That is why I teach Bag Lady Clubs at 2 different quilt shops here in the Valley. <G>
The favorite patterns in both clubs are those by Joan Hawley, Lazy Girls Designs. She has lots of great styles of bags/purses and different sizes and such. All her patterns have photos to show the steps and sequence for assembling the bags.
Penny Sturges, Quilts Illustrated, is the designer of the Bow Tucks Tote and also has several different patterns around.
Once you start to make bags you will find that a lot of the details can be made in different ways. Find the way that is easiest/fastest for you and use it for any bag. (for example, fabric straps are going to be fabric straps. The differences are width and whether or not you add batting/fleece to the strap and how much you add. As long as you end up with a strap/handle that is the right width and length how you get there is pretty much up to you.)
Remember, when you are making a bag it is usually a utility thing. Yes it is wonderful if it looks great and is stylish, but...
Close is good enough. On most any part. If your seams are off a bit so what, the next time will be better. Do the best you can and improve each time.
Also, once you make a bag by the pattern you will see where and how you might want to modify it. The more you make the easier they are and so forth.
Have fun,
Pati, in Phx