Surveys on Network Coding I want to start learning about Network Coding:

http://en.wikipedia.org/wiki/Network_coding

Do you know any good survey (e.g. from IEEE Surveys and Tutorials) on the above subjects. I found some university courses on google but I'd like some recommendations from people who already read and know a good source. 

Thanks
Vasilis
As per Suresh's request (he is the boss after all) I am making my comment above an answer.

Emina Soljanin at Alcatel-Lucent Labs works on network coding and content delivery networks. She has written survey articles on network coding. See her web page. ect.bell-labs.com/who/emina. You can also check out her papers on content delivery via network coding and other means on the ArXiv.

I also want to say that network coding is a topic of much interest to theoretical computer science - there are several papers in TCS on this topic.