Review : Directory of Open Access Journals (Pdf), by Heather Morrison is a very good introduction to what is becoming a top-tier collection of journals.
Although some of the statistics are a bit dated (due to a strength of the DOAJ – they are adding journals fairly rapidly, and are currently past the 3,000 mark) the review hits the mark, making a great case for libraries to connect their patrons with this excellent resource.
from ResourceShelf