New Mac user having trouble with airport

I'm new to mac computers and just purchased my first one. Right from the start i have had a great deal of trouble connecting to the router in my house. Currently, I have to restart my computer to get the airport to work and establish a connection. Nine times out of ten it wont get a signal when i start up or wake it up from sleep mode. It says its off and it wont allow me to turn it back on. I called apple customer service and they managed to solve it briefly and i thought i was in the clear but, an hour after i got off the phone with them the problem came right back. I don't know a whole lot about macs but would appreciate any ideas or advice in resolving this problem so i can use the internet.

I replied to your other post.