WiFi should be straight-forward.
Click on > Settings
Then > Wireless & Networks
Then > Wi-Fi settings
(Then turn on Wi-Fi if not already on - add tick to box)
Then > Add Wi-Fi networks
In the pop-up box add your network name (it may detect it automatically). Then click on security and add type and password. Click save. It should then connect.
As for 3G, you may need to add VPN settings. Which network are you with (eg. Vodafone, O2, Three, etc)?