Well, first hint. All of those are tile-based.

Second hint. Squares, Diamonds, and Hexagons are just three different shapes of tiles. Two of them use staggered columns to close the gaps which are caused by being shapes not aligned to screen axes.

Third hint. There are more good tutorials out there on all three pre-rendered projection styles than I can shake a search engine at. So, here''s two decent search engines for you to shake some results out of.

http://www.google.com
http://www.altavista.com