My personal favorite product is glossy Mod Podge by Plaid.
This is a simple gnome earring that I made with wooden round craft disks. I drilled, painted and added this photo using mod podge. Once it was glued on, I covered the entire thing, photo and all, with glossy mod podge.
I also shared one of my projects last fall that had been published in Bead Trends magazine last May that included the use of mod podge. Here's a link to that blog post.
After doing a few searches, I found a great video by our pals over at Auntie's Beads that shows not only the steps for decopauging, but also for assembling this purple bracelet.
It's impossible to write a post about mod podge without including a link to the great Amy Anderson's blog, MOD PODGE ROCKS! Amy does projects constantly, including jewelry, and also shares LOTS of links to project how-to's from all over the web!
Now, once you get hooked on decopauging everything in sight, you'll want to check out the Plaid project page.
For anyone interested in creating resin jewelry pieces, but who didn't want to get involved in the chemicals, you have to check out this project by Cathie Fillian. She uses a mod podge product that is "dimensional" to create a collage charm. Great stuff!
I hope this helps!! :)