Wireless on Trisquel

Hello,

I am a Debian (formerly Ubuntu) user, and the only thing standing in my way of using a fully free system is my wireless card. I have been looking at the FSF's list of supported wireless devices at http://www.fsf.org/resources/hw/index_html/net/wireless/index_html/cards.html, but my question is whether all wireless cards will work with all wireless networks.

I don't know very much about wireless networking, but I do know that there are a, b, g and n protocols available. I have found that some of the devices listed on the FSF's page are claimed to work with the "n" protocol, but I don't know whether that is backward compatible with existing infrastructure.

I also am unsure as to which wireless cards will plug into my system. I'm not greatly knowledgeable about hardware, but I hope to take this opportunity to learn something and I hope you can bear with my ignorance. :-) Here is the output of lspci; I don't know which part is relevant so I've simply pasted the whole thing:

00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)
00:1b.0 Audio device: Intel Corporation N10/ICH 7 Family High Definition Audio Controller (rev 01)
00:1c.0 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 1 (rev 01)
00:1c.1 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 2 (rev 01)
00:1c.3 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 4 (rev 01)
00:1d.0 USB Controller: Intel Corporation N10/ICH7 Family USB UHCI Controller #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 (rev 01)
00:1d.3 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 (rev 01)
00:1d.7 USB Controller: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller (rev 01)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e1)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 01)
00:1f.2 IDE interface: Intel Corporation 82801GBM/GHM (ICH7 Family) SATA IDE Controller (rev 01)
00:1f.3 SMBus: Intel Corporation N10/ICH 7 Family SMBus Controller (rev 01)
03:00.0 Ethernet controller: Broadcom Corporation BCM4401-B0 100Base-TX (rev 02)
03:01.0 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller
03:01.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 19)
03:01.2 System peripheral: Ricoh Co Ltd R5C843 MMC Host Controller (rev 0a)
03:01.3 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 05)
03:01.4 System peripheral: Ricoh Co Ltd xD-Picture Card Controller (rev ff)
0c:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02)

I would appreciate any general advice you can offer, and even moreso I would appreciate specific suggestions of what product to buy given that I know almost nothing about the differences between them. If I can get my wireless working with free software, I will definitely switch to using Trisquel.

Thanks for your time,
Steven.