I don't use a lot of faxing technology (it's kind of outdate with email) but many people still use it so I thought I'd check out a few of the online faxing technologies out there. I've decided to initially check out MyFax. They have a free trial and it's dirt cheap to keep it if I decide it's something I'm going to use.
The way it works is very simple. When I want to send a fax, I just send an email to <faxnumber>@myfax.com, or use their print-to-fax tool (kind of like print-to-PDF). When I recieve faxes on my personal fax number, it goes straight to my inbox. Seems like this would be pretty difficult to screw up.
Check them out at http://www.myfax.com/ for more information, and no, I don't make any money off the link.