I use Freehostia it's a great free no-ads host and allows you to use your own domain name. The web host will give you specific instructions for FTP configuration for that host. Most web hosts also give you an online file uploader you can use if you don't feel comfortable with FTP.
For FTP I like the program Fugu. Though you won't be able to use it until you have a host, which will give you server information for connecting to. I host my own web site so I can't recommend any web host.
Just try googling free website hosting or something similar and see what comes up. I used to use freewebs until they started forcing huge "Made with freewebs banners", so I switched to freehostia.
FTP = File Transfer Protocol
Once you have a web host they'll give you a user name, password, and server name. You'll use these 3 things with an FTP program and it'll connect to the server. Once the connection is made it's very similar to having just another Finder window open and you can drag and drop files to or from the server. How exactly you interact with the FTP program will depend on its features.
There's really not much to it once you get the information from your host.