I just bought my first home, and I'm on a low budget and had to do something about the gross green countertops that are in my bathroom.
Get a roll of Contact Paper.. You can find it at many stores and they even sell special 'countertop' contact paper on the internet. I found this roll for $2 and decided to try it out before I bought the expensive stuff.
It works perfectly!
Unroll the contact paper on your countertop and cut it to fit your counter. For the sink, I laid it ontop of the sink and pressed around the edge of the sink with my fingernail to crease it, then I cut along the crease.
**Make sure your counter is VERY VERY CLEAN first!! Even the slightest speck of dirt can cause an air bubble!
You can let the edges hang over and slice them off with an Exacto-blade when you're done. It makes for a nice clean edge.
When the counter is clean, keep it wet with some water and dishsoap (any liquid soap will work). Not soaking wet, but damp.. This allows the paper to slide around as you position it and makes things way easier.
I used a squeegee to carefully peel off the backing and apply it to the counters, if you don't have one try to find something that would work the same way.
If you press down the paper with your fingers, it will cause tons of air bubbles!