I am not an avid reader but I'm reading more these days than I used to. I'm sure I have about a dozen half read books next to my bed with bookmarks gathering dust. I was at Borders the other day and gathered together about 8 Horus Heresy books and contemplated purchasing at least the first few... then I put them down and used my 30% off coupon to finally purchase Warhammer Invasion. My question is: If I am going to start reading some Warhammer... and I plan on picking up Horus Heresy (the game), should I start with these books. Or perhaps there is a better series to start with???

IMHO, Horus Heresy books are worth your money. In short, they definitely show just how different the reality of the 31st millennium is compared to the "default" 41st millennium and while they are still nowhere near (in terms of the timeline) the actual Battle for Terra (which in itself is rumored to be depicted in the final book(s) wrapping up the series), the authors manage to fill in the most interesting white spots of W40K fluff and convey just how rapidly everything starts to go downhill. Being an avid reader of the series I heartily recommend it, if only to get a better a better understanding of the era and thus the background of the upcoming HH game.

Agree the HH books are awesome and I would reccomend you should read them if you like the W40K universe.

I love the stories from Abnett and McNiell and looking forward to read Prospero Burns

  Yes, you should read them. At least some of them. Here is my list of the suggested books in the order they should be read:

1. Horus Rising

2. False Gods

3. Galaxy in Flames

4. The Flight of the Eisenstein

5. Fulgrim

6. Legion

7. Battle for the Abyss

These seven will give you a good knowledge of the how the Heresy takes hold of the traitor legions and how it begins to spread. I have ommited Book number six in the series, Descent of Angels, because it doesn't really deal with the Heresy but with the Dark Angels founding.

But you forgot Mechanicum. It is about the Heresy and the AM is also present in the game.

Ah,  but I am just about to start to read Mechanicum.

 Yes you should.

But, as an alternative, you could just waltz in any 40k store and borrow from a space marine player their codex. The previous edition (4th ed), IIRC, is a little more detailed. These codexes give you a good rundown about Horus Heresy.

The Horus Heresy books are good, but they are waaay back before the event.

Thanks for the replies! I have picked up Horus Rising and I just started reading it. It's definitely sucking me in.

I love the opening to Horus Rising: "I was there, the day Horus slew the Emperor."

I'm half way through it. I'm loving it!

Mechanicum is fracking awesome, just love the novels by Graham McNeill.

Reading Tales og Heresy and there is a lot of nice short stories there.

can't wait for A Thousand Sons

 The books are amazing, especially the first three. Surprisingly well written.. although I knew going in that Dan Abnett kicks ass.

I even liked Flight of the Eisenstein, not because of the different perspective but because you really get to see a primarch up close (Mortarion).

Have to confess I went out of order after the first four books, but it doesn't really matter.

Currently reading A Thousand Sons. Magnus is awesome.

I have to confess that I was really excited to read this epic story. I picked up the first three books and read them ravenously.

*spoiler alert*

After reading the 3rd novel, I now realize that they are REALLY milking this franchise and are nowhere near to the invasion of Holy Terra. I was hoping for a 3 part story, myself. Horus is a good guy. Horus becomes a bad guy. Horus gets grounded by his dad. Done and done. But looking at the book outline for the next few releases, this story may not conclude until a dozen or so books... which is far beyond my patience at the moment. I'll wait for a compilation.

I just finished A Thousand Sons, and I can highly recommend it. I thought it was one of the stronger books in the series, next to Legion.  Some parts of the overall series gets a little slow, but anything written by Abnett or McNiell is pretty much going to be a good book.  

HH (the series) is really good.  Actually, just about all the 40k novels Ive read flow the same way.  If you finish HH just jump over to all the Gaunt's Ghost's novels,  theyre just as good. 

or the books with the Ultramarine 4th company.

Love the one where their are fighting Nids.