Hi fellow Newbees. If you are having trouble with wireless network my I humbly suggest that you try a couple of simple things first.
1. If you are on a laptop check that the network function key is turned on. Mine is on F12 and has a bluish light for ON and reddish light for OFF.

2. Go to System > Administration > Users and Groups > Advanced Settings > User Privileges Check you have relevant permissions for Connecting to Wireless Networks and the Internet. (Also turned my audio on here after much trial)

I discovered these after spending hours following up suggestions on these forums. They might not solve everyone's problems but they will hopefully save some of you from fruitless searching

You may also type the command 'ifconfig wlan0 up' or 'ifconfig wlan0 start' from the terminal