Are you wondering whether BackTrack will work with your chosen device or laptop?
The first place to look is in the Hardware Compatibility List. Check for your device in the forum, and read the relevant information to see any caveats about the support for your device (if any). You can also check the archives for information on devices supported under BackTrack 4 Beta and BackTrack 4 Prefinal, theres a good chance that anything supported under those older BackTrack 4 releases will also be supported under BackTrack 4 Final.
For wireless devices you should first check the Wireless Drivers page on the wiki here. Then there is a thread here that you can check out, as well as the forums above. Some recommended wireless devices are also listed in a thread here.
If there is no information about your specific device here on the forums you can also search the Internet for general Linux support information about the device in question. For laptops, you will sometimes be able to find the names of specific hardware devices included with the laptop, which will allow you to research those specific devices to see if they are supported under Linux. In most cases, hardware that is generally supported in Linux will also be supported by BackTrack, with the exception of some devices that are only supported in later versions of the Linux kernel than the version that is installed with BackTrack.
If you can't find any specific information on the Internet about the device you are interested in, it may not be supported under Linux at all. The last thing you can try is to actually try the device out with BackTrack and test for yourself to see if it works. If it does, make a post about it on the Hardware Compatibility List, and let us know what features work, as well as any special configuration steps you may have used to get it working. Even if the device doesn't work, or only works partially, make a post about it anyway and give details, that way other people will know that device does not work with BackTrack.
I really want to encourage people to share information in this way - we require the support of the community to build the list of supported devices so people can know which machines and devices they can use BackTrack with.
What you shouldn't do is to post a question asking whether a particular device will work. If the methods above don't work in allowing you to find out whether your device is supported or not, and the device is not on the Hardware Compatibility List, chances are that no one who reads your thread will know whether the device works under BackTrack either. Don't count on a BackTrack user who happens to own that device coming across your post and responding within a reasonable time frame....