First time I read this was about 2 years ago, when I bought the first issue of this short series (about 24 issues altogether). The first issue was pretty good, but I lost track and forgot about it for a while. Buying comics every month is a lot of work, so I usually just wait till the entire series is complete and download the whole thing. It sure beats waiting a whole month to find out what happens. And that will be very important, because this series is really hook-worthy.
If you are a person that is turned off by comics because it has to do with superheroes, don't worry, I am the same. I read a lot of comics, and almost none of them have to do with superheroes (except Watchmen, but that is about so much more...).
Girls is interlaced with a lot of witty and subtle humour mixed with some sci fi (sorta). Its a great story; I have just began reading, and already I am going to try to ration the series as it is short and I will be sad when I have nothing left to read. If you want, you can download the whole thing at: http://comicscollection.blogspot.com/2006/04/girls-comic-collection.html
If you have the dough, I suggest you buy the whole thing off ebay or something. This will tie me over till the release of Craig Thompson's upcoming Habibi.