Get thee down to your library and get one of the sunset books on making slipcovers,or go to any good book store,or fabric store.Seen them there as well.
You may also want to check HGTV's website,they may have directions.
Just don't put it together with a hot glue gun!!LOL
Kathi

Well aren't you the brave soul! Being not very good at sewing might be a big problem because you will need to make either very straight lines or good curves depending on how you plan to make your slip cover. Saying that, beside getting a good book with instructions, I would not try for the first time using material that you have spent a lot of money on because it may not be what you are imagining it to look like when finished. I have watched Trading Places and they make everything look easy and fun, but they are all doing something that they are good and experienced at doing. I am not trying to discourage you because we all start somewhere.

If I was not a very good sewer and never attempted this before, I think I would purchase a very inexpensive (like the $1.00 or $2.00 a yard from Walmart) fabric and make the slipcover and use it for a pattern for the future if you like the way it looks. JMHO. This may seem like a lot of extra work, but it could save you lots of $$$.

I'm slogging my way thru my first ever slip cover. I picked a very square arm chair, so making the pattern wasn't terribly hard. Since it's a chair the cat likes to sit on, and the kind I throw myself into, I wanted some really durable fabric. I bought a 10'x10' canvas dropcloth at the hardwarew store. It's a nice unbleached color, and the distinct grain is making it easy to sew pretty straight. (If I could just make the time to sit down and finish it!)

I'm taking the easy way out as far as fastening it; a double strip of velcro down the back, which won't be seen.