Ana Maria Menezes has just published a 53 page free ebook titled 20 WEBTOOLS Applied to Teaching. In addition to some well-known services like Animoto, Ana Maria has included some lesser-known tools that could be particulary useful for ESL/ELL instruction. You can download the ebook from Issuu. I also recommend browsing through Ana Maria’s blog, Life Feast, if you’ve never visited it.

Here are some related items that may be of interest to you:
Free 33 Page Guide – Google for Teachers
Beyond Google – Improve Your Search Results
Free Guide – Making Videos on the Web