I teach high school Spanish grades 9-12 and use the series Paso a Paso. Here is their website:
http://www.phschool.com/atschool/paso/ I like levels one and two a lot. Level 3 is alright but you will need to supplement the material that the book gives you with your own wks, games, etc. so that the students get enough practice. Level 3 also goes over a ton of verb tenses, just about every chapter does a new verb tense. One good thing that level 3 has is stories for each chapter in the back of the book. Paso a Paso also has a website so students can get extra practice and teachers can find ideas for other extras like projects, crosswords, etc. You could probably buy these textbooks used if you wanted to save $$$.
At my school we are going to be buying the new version of these textbooks, which is the series Realidades. I already use the videos from this series because they use some of the same vocabulary words as the Paso a Paso series. The videos, which have wks too, are great. Here is the website scroll down to Realidades:
http://www.phschool.com/foreign_languages/ They also have online extras for teachers and students.
If you are looking for spanish readers/literature as well I recommend the "Leer En Español" readers. There are readers for every level of spanish ability. My students love the murder mystery, La chica de los zapatos verdes by Surís, it is a level 2 book and pretty easy to read. If you prefer more classic authors you can also find readers by Cervantes, Bécquer, Galdós, Zorilla, Ibáñez, Bazán and Rojas. Here is an older website I found with some of these readers (there are more hoy en día) you have to scroll down a bit to find the Leer En Español series:
http://www.continentalbook.com/catalog/spanish/spreaders.html These books are great because they come in a variety of levels so there is something for everyone, however, they don´t come with quizzes or wks that I am aware of. There is a glossary of words in the back of each book. What I do is read each book and write a list of words that I think should be vocabulary words and then give them quizzes on the words and what is happening in the story.
I hope this information is helpful to you.