I haven't stayed at the Pop Century, but I've stayed in all of the All Stars which are basically the same idea. The theme for all of these hotels is fun and over-sized. The rooms are about basic (think Holiday Inn, or a little nicer than Motel 6), but very, very clean.
You can find more information about the resort (as well as reviews and first hand reports from people who have stayed there) here:
http://www.allearsnet.com/acc/faq_pop.htmand here:
http://www.mouseplanet.com/cgi/reviews/do/display.cgi?product-sku=wdwpopcenturyYou might also want to check Mouse Savers for special rates -- I've heard of people staying in the Moderate category resorts for the same price as the value resorts -- here:
http://www.mousesavers.com/And for general information and help planning a Disney Vacation, I strongly recommend All Ears Net, here:
http://www.allearsnet.com/I think you could have a wonderful time at WDW. There are so many things to do and you could stay busy for longer than a week there. If you decide to try to spend a day or two at Universal, I'd recommend sharing a taxi for the ride over -- the sites above probably list companies and rates.
Food can get expensive, but portions are generally huge. I'd recommend stocking breakfast food in your hotel room (many of the hotels offer fridge rental and some of the shuttle companies will stop at a grocery store on the trip from the airport to your hotel), carrying your own bottled water and some snacks (technically you're not supposed to, but I've never heard of anyone being stopped at the gate with food), and planning on one big meal a day. At the sit down restaurants, entrees are usually big enough to share. Alternatively, you can often make a very filling meal out of an appetizer and dessert. (As a rule, when I go cheap on a meal, I tip very generously.) Also, if you call ahead, WDW can handle any special dietary needs, from Atkins, to Vegan, to Wheat-Free and Allergic. The sites above also offer restaurant reviews and information about dealing with special dietary needs.
A book I'd recommend is The Unofficial Guide to WDW:
http://www.amazon.com/exec/obidos/tg/detail/-/0764559729/qid=1101922345/sr=8-1/ref=pd_csp_1/102-7432435-3120159?v=glance&s=books&n=507846Whatever you decide, I hope you have a wonderful vacation.