You can purchase stabilizer at JoAnn's, it's on the bolts with the Pellon stuff. Inexpensive and good way to see what you like before you go out and spend lots of money on rolls of stabilizer. Use a medium cutaway for most things, use an iron on for stretchy things, tear away for towels with a wash away topper to keep the stitches from sinking into the towel. I love Metro Thread
www.metroemb.com right now 1000M spools are on sale for 89 cents, they also have assorted packages, great for starting off. Polyester thread is all I use, it can be bleached, some people like the shininess of Rayon but you can't bleach it. I use Embird software, buy the basic module and Iconizer so you can see your designs. Go to the thrift store and buy t-shirts, woven shirts, towels, etc. Have a play date with yourself and try out the different fabrics with different stabilizers. Then wash the test items and see what happens. If you get puckers it may be you stretched your fabric when hooping, or the stabilizer shrunk. I always steam iron my stabilizer and wash the item to be embroidered so it all shrinks before I embroider it.