I would HIGHLY advise you not to use 1and1.com. I used it, hated it. It was slow and they oversell their shared servers. There are literally hundreds of hosts out there and noone is going to give you the name of the best host..because there is none. There is only what is best for you. Pricing/space/etc all come into play. Check the web developer forum on this site for help on hosts. I would recommend asmallorange.com or bluehost.com
Next, the software you use to run your site. How much are you willing to spend? No limit? Then go Vbulletin (i use it, this site uses it, many other big forums use it). If you're looking for a something simple and cheap..phpbb is fairly good and stable. There are others as well but its up to what you want to do with the site.
Lastly, you'll need a FTP program to upload the files from your computer to your server. The hosting company gives you information to log into their server and you will then upload the forum software as well as whatever else you want on the site. It's fairly straightforward if you invest some time into it. As for programs (Transmit, Fetch, YummyFTP, Filezilla) all range from free to $$. Again, it's up to you.
PHP files are not PC or Mac specific. Any forum software will work.