Just noticed that your first 2 posts were back in 2005, and you haven't posted since, so I don't know if you're a little out of the loop now.
Blood Bowl is now using the Competition Rules (or CRP, though you may see it referenced as LRB6) - it is downloadable from the GW website, under the Resources page:
http://www.games-workshop.com/MEDIA_Cus ... _Rules.pdf
If you buy a boxset from GW, the rules in the box will be LRB1 (Living Rulebook 1), but these are out-dated. If you buy one from eBay (or elsewhere) the rules in the box will be either LRB1, or the older straight 3rd edition, depending on the age of the box.
None of these rules are official anymore - the CRP I linked to above is the current official rules set.
Currently an ex-Blood Bowl coach, most likely to be found dying to Armoured Skeletons in the frozen ruins of Felstad, or bleeding into the arena sands of Rome or burning rubber for Mars' entertainment.