Catch 22 - You can not get credit until you have credit.
A couple of ways to start:
I'm sure Captial One is dying to give you credit, don't charge what you can not pay, and watch the 10 - 15 offers from them that you will start to get in the mail each week.
Maybe a department store charge card, like Sears, then Sears will offer you either a Discover Card or Sears Master Card, or maybe both.
Then they have these cards that you put money down first, then you can use it until you get low and/or add more money to it.
I'm not really familiar with the deal you were trying to get from Dish, but you may have some other choices, including you can elect to boycot them completely.
-- Maybe buy a 311 or 322 receiver from Radio Shack.
-- Order another receiver from Radio Shack, online, or a local retailer.
-- Then call dish and order programming for it. It seems like they would turn it on, since they could turn it off at any time. They might ask for payment first.
-- Pay up front, even if its sending them a check in advance.
On the discount, I believe there is a form you can download and send it in with your first bill, or a online print out of your bill, to get a $100 rebate. Again, there are certain requirements to meet on who qualifies for the various rebates.