www.divx-digest.com and
www.doom9.net are two sites that are about divx. they have everything needed for creating a divx movie. Both of them also have tutorials for you, to learn a few things. It's not an easy thing to say which programms are the best. All of them have their advantages and disadvantages. For example one programm would be very easy to use but be a little slower than another. There are some programs that stand out though. Reading some tutorials will also help you decide which programs you want to use.