I strongly suggest you to use GIMP instead of using any other program. But it is true that some of the beginners may have problem with the use of advance level tools available. This you can see in many tech forums, where people ask about programs similar to M$ Paint which can perform advance level tasks (like multi layering, adding cool effects, supporting more file types etc) in a simple way.

This edition of techblog is about such type of solution (ofcourse, free one) : Paint.Net

This solution allows you to add multiple layers and supports unlimited undo. Another interesting feature is that it supports special effects!

If you have this freeware, you may not require any of these solutions – Adobe® Photoshop®, Corel® Paint Shop Pro®, Microsoft Photo Editor.

Support for unlimited history makes this tool quite unique. There is an active Online Community that constantly adds new plugins. You may download more plugins from here.

The website also has a resource section that contains tutorials to hack the solution!

Go ahead ‘n give it a try !