@Sabredog
I agree that the Gaunt series by Dan Abnett is excellent, and may be a good jumping off point for many; I started 40k with the Ravenor and Eisenhorn novels but I had some background info from Space Hulk gaming and reading White Dwarf magazine.
I've always found the Ultramarines to be a bit starchy really, but love Grey Knights and Soul Drinkers novels. You can't go wrong with the Space Wolves omnibus as a start point though as it provides TONS of detail on creating the Astartes.
|