I have only used it a little. I made some chalkboards out of cabinet doors. On one I mod podged sheet music to the frame and another used coffee bean scrap book paper onto a frame for a coffee themed room. I used matte but have some gloss that I haven't used yet. Got them both free at the re-use center. :) I have some wooden coasters and box that I am debating mod podging scrap paper or doing mosaic.
Mod Podge is actually pretty easy to use, it just takes a little patience the first time. My advice is start with something flat, like a picture frame. Don't go overboard with it. Work with thin coats and use an old gift card to help smooth out your paper/fabric. Make sure to let it dry before applying a top coat. I'll post a few links to some Mod Podge posts I have done so you can see...they are step by step tutorials. Please let me know if I can help in any way!