Here is the first model I have painted for my Lizardmen, I decided to start big and paint my Stegadon.
it is a bit shiny. i recommend army painters anti shine (though there are plenty of products that work)
The best matte sealer i've found is the Testors dullcoat It's idiot proof in that it's very hard to get it to dry thick on the model, almost always will dry in a super thin unnoticeable layer. Helps protect from chips/damage/finger wear, and it will knock the gloss out of the model. It's only a couple bucks a can at Michaels, but up to $7 a can if you go to a hobby store.