The West Marches – Blog post by the creator of the original West Marches campaign. Great overview of what a West March campaign is, and why he made it.
Getting There is Half the Fun – Expanded exploration rules by the Angry GM. Great read.
Hexographer – Hex based map maker for all your hex crawling needs.
Collection of Resources – A compilation of useful West Marches tools.
The Hexenbracken – A hex map with encounters/creatures that are occupying each hex. Great ideas and inspiration.
In Praise of the 6 Mile Hex – A break down of pros and cons of a 6 mile hex.
DM's Toolkit 