Well the first group I started off with which had a Blues Influence was The Animals and I reckon that while they aren't solely Blues, they do excellent covers of Blues. I think after that I got Manfred Mann which started as a Blues band and The Yardbirds were also another group which started off Blues. Perhaps my first trip into deeper Blues music was John Mayall's Blues Breakers album with Eric Clapton. It took quite a bit of listening just to get used to it. Another good one which have that connection is The Spencer Davis group. Personally I think to start out with Blues, it's great to get into those forms of Blues even if it's not solely Blues Music, they have that Influence which I think helps one influence in deciding if Blues Music is worth listening to or not. But what do I know.