You should be able to just start using the AOL email client program to get mail going forward. Once you sign in to AOL program the mail link should get you to your messages.
To transfer messages out of Incredimail see the link below.
Unless you have specific needs and are confident in your backups. For most folks that is a good thing.
I use email from Gmail for somethings and my ISP for others but I probably have a better organized than average backup plan. As I do that stuff for a living.
If somebody is using AOL[anything] its likely they aren't a sophisticated user, hence Gmail would be a great solution. Simple, cheap available anywhere and masses of storage which Google backs up for you.