What are current PCB surface protection techniques?
The easy answer is that you should look at the options your board house offers and then research that.

Common options I've seen are:


HASL, Hot Air Solder Leveling: They bascially coat the entire board in solder and use a air knife to blow the excess off, it's cheap but it can leave a slightly uneven surface, which might mean something if you are doing BGAs.
OSP, Organic Solderability Preservatives: A very thin coating that keeps oxygen away and evaporates when soldering, it looks as though there is just bare copper on the board.


This page has a good description of these and other finishings:
http://www.multicircuits.com/pcb/tech/surface_finishes.html