Network between two remote location within City...

I am having one office at one location (LAN network address is 10.10.10.0 / 255.255.255.0). Other office (LAN network address is 10.10.10.0 / 255.255.255.0) is approx. 50 km away and both of these is connected through a Wireless Link. This Wireless link is having address 169.254.20.4 / 255.255.0.0 at first office and 169.254.20.5 / 255.255.0.0 at second office. Now I want to share Internet and Local PC from one office to another but with restrictions and security. What is the easiest and cheapest soloution to solve this problem. I just have to transfer files and normal remote desktop or netmeeting between two offices. I also want to share the Internet in my second office but with full restrictions and real time logging also.. Please advice. Thanks