This show is quite possibly the funniest anime out there. A huge favourite in the anime circles; people have been waiting a long time for this to be released.. unfortunately, the name and premise is hard to sell to people unaware of it. It is basically a slice-of-life comedy series, very much so in the vein of Peanuts (snoopy, charly brown, etc), except that it deals with a bunch of Japanese school girls and the humour is alot more emphasised.
I can't stress enough that you should pick this up and at least try it out. There's no epic storylines or character arcs, so you'll easily be able to decide if this is your sort of series or not by the end of the first disc. Sometimes simple entertainment can be the most rewarding.