If you want to do things seriously, I recommend getting a high range antenna/adapter.
Here is a nice adapter~
http://www.amazon.co.uk/Alfa-AWUS036H-Upgraded-Wireless-Long-Rang/dp/B000WXSO76/ref=sr_1_3?ie=UTF8&qid=1332208729&sr=8-3If you want to go even further, you could get this~
http://www.amazon.co.uk/2200mW-Booster-Antenna-802-11n-STRONG/dp/B0034FAS0K/ref=sr_1_6?s=electronics&ie=UTF8&qid=1332208789&sr=1-6No doubt the latter will cover your whole street.
As stated, Backtrack is the best option, it comes pre-packaged with everything needed.
If you own a router, you could perform attack on it, to practice.
I started out with WEP, unfortunately, even though this type of encryption is still used, it's near enough long gone, however you're sure enough to find at least 1 on every street in the UK. (Mostly)
WEP is great for a beginner, and it's a fast process.
After that, go for a stronger encryption, WPA-PSK, try bruteforcing the key with wordlists (You need the 4 way handshake for this) This is very slow and could take days..
A new tool has been released not so long ago, called Reaver.
It exploits the WPS feature of most networks (I've heard every network device has WPS enabled on default, I've also heard on some devices, it's not even possible to switch off)
And allows you to bruteforce the PIN, which is used with WPA.
I tested Reaver on my own network this morning, manually turned on WPS in my router config and bruteforced it.
Got the PIN & Password for it in 3 hours
Good Luck!