This is the list of questions most commonly asked by the newcomers to the Linux wireless networking land, along with the answers.
Q: Is my XXX model device supported?
A: Forget about XXX, what really matters is PCI or USB (depending on the bus your device uses) ID pair: VID:PID. So to find out if your device is supported, use lspci -nn or lsusb to learn the ID pair.
Then navigate to Google and type the request in the form "VID PID" site:cateee.net/lkddb/ (e.g. "14e4 170c" site:cateee.net/lkddb/). If there is a hit, this will allow you to learn which driver to use for your device. If there is no, the device is most probably unsupported (though if you are really sure some driver should support it, you can try modifying the driver source to add the ID, or use newid sysfs node for USB devices).
Q: I still have problems using my device
A: Follow this checklist:
Install the latest stable compat-wireless
Navigate to the driver page corresponding to your device to learn about limitations or additional requirements.
Read dmesg output carefully, paying extra attention to firmware-related messages.
Use rfkill list to see if there are any rfkill-related issues, there must be no kind of blocks present for you wireless interface. Sometimes there is a mechanical switch that needs toggling for leveraging "hard" block.
Q: iwconfig tells me bla-bla-bla error
A: Please use iw and wpa_supplicant instead. iwconfig is using deprecated way of communication with the kernel which is supported only in compatibility mode, has some limitations and might be removed altogether at some point.
Q: I've installed some driver from somewhere, now i have ra0 interface etc...
A: If you are using drivers directly from vendor (and not from upstream Linux or compat-wireless) please ask your vendor for support through its support channels, linux-wireless has nothing to do with that.