I would suggest you contact Pfaff firstly to see if you can obtain a manual, its always worth having the one for your machine. I presume you are in the USA? if yes, go to www.pfaffusa.com
or ring toll free 1-800-446-2333 Monday-Friday 8:00a - 4:00p CST or email email@example.com
or go to www.pfaff.com
then choose your own country then go to "contact us". and find the details.
Using a rolled hem foot is the same on all sewing machines, you are introducing the cut edge of the fabric into the front of the foot and it rolls the cut edge twice, as you seam over it. Its fiddly, you need a straight trimmed edge, and you have to keep the same amount going into the foot for it to work. You can either straight stitch or do a small zigzag over the fabric. Getting it started is the hardest bit because you need something through the foot to stitch on so it doesn't just get pulled into the hole on the needle plate.
try this link http://sewing.about.com/library/sewnews/library/aatech0803.htm
for a bit more info on this, some machine makes sell a 2mm, 4mm or 6mm foot for different weights of fabric and finishes. You can buy accessories for your pfaff from www.sewingpartsonline.com
or from Pfaff. Pfaff website even has free projects and a newsletter for customers.
Just put the foot on, lower the pressure foot onto the edge of the fabric, do a couple of straight stitches, then raise the pressure foot and pull the fabric back an inch, so you have something to hang onto at the back, then put 1/4 of fabric into the open part of the foot, hold it there, lower the pressure foot and start stitching, keep a bit of fabric turned in in front of the foot so you help it go into the foot and try to keep it a constant width, trial and error, you'll soon get the hang of it.
Piping can often be done with your zipper foot, you just want to encase the piping cord with a bias cut fabric strip and stitch as close to the edge of the cord as you can to hold it nice and tight. Then put the piping strip between two pieces of fabric and again stitch close to the cord so the first line of stitching doesn't show. Some machines, the zipper foot will have a guide so you can squeeze the cord up against the foot. Here is a link for piping techniques http://sewing.about.com/od/techniques/a/covercording.htm
and covering cord http://sewing.about.com/od/techniques/ss/cordingpiping.htm
Just cut the bias strip width to suit your cord width, join the bias strips together if you want lots of length, then wrap fabric around the cord, right side out, put it under the zipper foot and stitch through the fabric as close to the cord as you can, on some machines you can adjust the needle position to get close but check your manual for help on this, you don't want to strike the foot, just sew up close to it.
I haven't done double piping, but I presume you would sew two layers of piping on top of each other?
I've got a old "Sewing Soft Furnishings" text book that I found at the op shop for $2, the images are daggy but the techniques don't change, most furnishing stuff is just taking measurements, adding seam allowances, and sewing straight seams, so the machine doesn't have to be fancy, or need lots of accessories, just know-how. What you do need is a strong machine to sew upholstery fabric, many domestic machines just won't handle heavy weight fabrics too well. Large sized needles 110 size will be important too.
I'd suggest you try one of Debbie's free pillow guides as a start http://sewing.about.com/lr/free_pillow_projects/271734/4/
, go for something without a zipper at first, and once you've made a couple of easy pillows, your confidence will grow.
Good luck with your Pfaff and enjoy your sewing.