Jess I did a LOT of reading online on my specific car about how to take everything apart. Honestly THAT is the hard part. Does your car have a sunroof? Mine does so that was a little tricky. Basically I got everything I needed from JoAnne Fabrics. I bought a material I liked (fleece works easily BTW). You need a fabric with a little stretch to it to make it easier. A good adhesive is crucial. I used 3M Professional Strength spray adhesive. It's basically really high quality spray rubber cement so it also doesn't stink up your car with funky chemical smells which made me VERY happy. What kind of car are you working with I may be able to send you some links.
I also did my first stereo install EVER yesterday Now I have HD radio and I can use my iPhone, yay, yay and YAY!!!! I can't believe I was going to pay BestBuy $100 to install my stereo! I HIGHLY recommend Crutchfield. They are an online store and they are absolutely wonderful. Great instructions and they give you all the connectors, harnesses and brackets you will need to do it right. They also have online support which is awesome too. Great company.