New English File:

http://www.oup.com/elt/global/products/englishfile/

Total Engish:

http://www.pearsonlongman.com/totalenglish1e/resources/index.html

New Headway:

Choose first the level you think (click on the book cover) and a new menu will appear with different exercises

http://www.oup.com/elt/global/products/headway/?cc=global

Solutions:

Choose first the level  clicking on the book cover and start doing the exercises

http://www.oup.com/elt/global/products/solutions/?cc=global&selLanguage=en

Smart choice: (American English)

Choose first the level and start doing the activities. There are songs and you can play the karaoke. Enjoy them!

http://www.oup.com/elt/global/products/smartchoice/

Adventures:

First choose what you want to do. Then, click on the level and start doing the activities

http://www.oup.com/elt/global/products/adventures/?cc=global&selLanguage=en

Attain: (only pre-intermediate and intermediate level)

http://www.oup.com/elt/global/products/attain/?cc=global&selLanguage=en

Engage: (from beginners to intermediate level)

http://www.oup.com/elt/global/products/engage/?cc=global&selLanguage=en

Horizons :(from false beginners to intermediate level)

http://www.oup.com/elt/global/products/horizonscee/?cc=global&selLanguage=en

New Hotline : (only starter and elementary)

http://www.oup.com/elt/global/products/newhotline/?cc=global&selLanguage=en