To get started, you can look at these sites (among others) for a beginner's kit of equipment:
Austin Homebrew Supply
Normally the equipment kits do not come with a brew pot. For partial boil extract with grains, five gallons is nice but you can easily do it in as small as a three gallon (12 quart) pot as well. Just boil water and extract to equal about 2.5 gallons of water and top off. You don't need a secondary fermenter but they are nice to have; personally I prefer the plastic Better Bottle carboys over the glass and I think most of the suppliers will substitute (may affect price, I don't know). But others will (correctly) tell you that with care you can use glass for years without any problems . . . I just worry about the high consequences that might
occur should there be a slip with a full glass carboy. You will also need a grain bag for steeping the specialty grains, though you can "brew your own" (pun intended) with a large piece of cheesecloth.
As to what to brew first, I would start with an "extract with grains" ale kit from a homebrew supply house that puts together tried and true recipe ingredients for you. The links below are to the index of recipe kits from some online suppliers:
Austin Homebrew Supply
Pick an ale that sounds like what you would want to drink and order the recipe kit. You will need a yeast to go with it -- for starting out, order a dry yeast and get a couple of spare packages.
I would also take a look at the site where John Palmer has the first edition of his book How to Brew
available online. The first of the links below is for brewing a very simple extract, a Cincinnati Pale Ale. The second link talks about adding specialty grains. You can use whatever ingredients kit you buy and follow the process Palmer outlines.
The above sections will get you started, but the more of the book you read the more you will understand what you are doing. I would suggest ordering the book as well. It gets you the latest edition and it is handy to have around. The one thing I would ignore in the Palmer specialty grain section is the line on removing the steeped grains: " Remove the grain bag from the pot, giving it a squeeze to drain the excess wort and avoid dripping on the stove." Don't squeeze it; I think doing so can cause harsh tannins to be released into the wort. What I (now) do is to put the grain bag in a strainer that I sit over the brew kettle and let drain for about a minute.
There is also a Homebrewing Wiki here at homebrewtalk.com: Wiki
Lots of information there. And, of course, these forums are great for asking questions.
Edit: Oh, and I forgot to mention, it's a great hobby! A ton of aspects from the tinkerer trying to constantly play around with the brew equipment to the hobby chemist getting deep into the science behind brewing, yeast cultivating, mashing, to the cook who loves to tweak the recipes looking for the perfect beer -- there's something for everybody.