I first discovered Michelle Tea when I was in San Francisco and kept seeing her book 'The Passionate Mistakes and Intricate Corruption of one Girl in America'. The cover kept drawing me in (even though the cover is pretty odd) and I eventually bought it... and ultimately everything else she has written.
The blog also has interviews with lots of writers and reviews of books so am excited to discover some new authors. It also sells these t-shirts:
...that one on the right says 'you got the styles eileen myles' - I think I could do with that one.