Although I've always worked at a school with a basal reading program (either Houghton-Mifflin or Open Court) I have never been a fan in the "one-size-fits-all" approach of the reading materials provided. Students who are not right in the middle or either bored or overwhelmed by the texts, depending on their ability level.
This is why I love guided reading. Once students are leveled, I can give students books that are just challenging enough for their level and keep all students engaged. Unfortunately, I've found that plentiful guided reading libraries are rare in the low-income, inner city schools I've worked in.
Luckily, there is a website for guided reading books that I've been using for the last few years. Reading A-Z is a website that allows (paying) members to download leveled books for printing and copying. The website has a correlation chart for both DRA and Fountas and Pinnel leveling systems and print the correlation on each book.
You do have to make the books yourself by folding and stapling which takes time, but its a much lower up-front cost for schools. (About 70 dollars a year). One could argue that with the cost of ink and paper it might even out with the cost of a traditional guided reading library, but I haven't found that argument to work with cash-strapped schools. I think it's a great resource for those who don't have access to a full guided reading library. Anyone else have tips on acquiring a guided reading library?