How to Connect Windows 7 Laptops and Android Devices Using WiFi

I have two laptops running Windows 7 and one android 1.6 device (apad). All of them support wifi. I have one 3G USB modem. I want to:

1. Connect USB modem to one laptop. I can access internet on this laptop.
2. Connect to other laptop using wifi and share the internet connection. I should be able to access internet on both laptops.
3. Connect my first laptop to android device using wifi. I should be able to access internet on android device also.

How can I setup this network. If required, I can also use ethernet. I have LAN cables and a 8-port Dlink switch.

Note: I can access internet on all three devices by activating Mobile APN on my Samsung Wave mobile phone. But this uses an 2G internet connection (slow speed). I want to do the same using my 3G USB modem.