If you've read any other parts of this site, you're realized you're going to need a web hosting package to show off your work. The web hosting package is the "dot com" and you're custom "@ dot com" email address that you'll be using for your web design business. You can learn about setting up your first dotcom here, but please read the rest of this page first.
You really need all your "designing" stuff in one place. You're going to want a phone number that shows in the public database (yes, every web site has a phone number, you might not know that!) and you'll need a "never-change" e-mail address to tie to your web hosting package.
Basically, imagine reallycreativename.com. When someone looks up who owns the site, it's going to list an e-mail address, phone number, and street address. (If you're ordering hosting, look into a privacy add-on to keep your real address safe.)
You don't want that e-mail address, and that phone number, to call your real, regular e-mail and real regular phone! So, I suggest you create a Google GMail account, then once logged into Google, go to http://voice.google.com/ to create a virtual USA phone number. It's free.
Now, in your web hosting package, set your account owner's email to your GMail, and set your phone number to your public free Google number!
Now, you can direct Google's free number to call any phone you own, but the public doesn't have to know your own private number to call. And it's free!
I do, however, suggest that you use a non-shared telephone for your design calls. (Phones used by other family members are a big no-no.) The cheapest way to get this done is to get a TracFone, it's no contract and costs about $10-$20 a month. You'll get a phone number, voice mail, caller id, texting, all that great stuff for that price. You can then go into your free Google USA Number and edit it so it rings that TracFone when someone calls your Google number! :)
This is the TracFone I use for my designing calls:
Now that you're paying $10-$20 a month for a TracFone that'll check your GMail just fine, and makes great calls on the AT&T Network, put the $80 a month you're saving by -not- having an iPhone into getting an iPod Touch instead ($200, once, no monthly fee) and then get a decent laptop, covered next!
Next section: Start with a Computer, Internet Access, and Image Creation Software