Personallly, the best Jail-Break out there is
AppSnapp . It will install an app known as Install.app , which will not only jailbreak your iPhone so other programs can unlock it, but will give you the option of installing several really REALLY kewl apps. However, check to see if it is compatible with your current version of iPhone software. If you do not have the 2.0 upgrade, you can get it free by simply using it to 'restore' your iPhone, Apple cant do much on that, you need that function (especially when moddin is involved). So, here is the iPhone 2.0 software Restore.
http://appldnld.apple.com.edgesuite....7_Restore.ipsw
As for Unlocking, this one is personal Favorite.
Hack that iPhone and iTouch: Jailbreak, Hack and Unlock 3g iPhone and Apple Gadgets: How to Unlock/Jailbreak Your 2.0 2G iPhone (Windows)
^2nd Best Guide Ever (Aside from pandora). After that, brandonsipodhelp is a great youtube channel to check out. His live revolves around apple, so you will find all your answers there.
***EDIT***
You need to click on the AppSnapp Link VIA your iPhone browser, or it will not work.