Forgive me if I'm telling you things you already know...
Making patterns just happens to be one of the hardest things you can do, which is why I've never tried. In this case, I think it'd be easier to find a jumper that you like the fit of, lie it out flat and take a pattern of it on paper. Front, then back. Mark where you want the yoke (the shoulder bit) which is usually 6-8inches down dependent on size and build. Then cut the two shapes from material and sew together with their respective pieces.
For a woman, create a 4inch dart, 2 inches under the arm of the front, coming in towards the breat, to a point. Sew the sides together and take in the sides with bull dog clips first (while it's on you) till you find it fits well, then sew it.
Sleeves are hard so I'd suggest getting a pattern from here...
http://www.independentliving.org/fashionfreaks/pattern.html
...otherwise the arm won't bend in the right places.
You'll need to measure down how far the yoke comes from the edge of the shoulder down the front and back pieces so you know where to put your point of the down arrow on the arm.
Cut your two pieces out and sew them together, and your yoke edges should meet. Then just fold under the end of the arms and sew them at a length that is suitable.
For a collar cut a piece of material four inches longer than your neck size and four times the height as you want the collar, then double it over long ways. Make sure it's stretchy or you'll never get it over your head! Sew the ends of the collar together at your neck size, turn it inside out and sit it on the ouside of the jumper neck, sew it to the jumper, and turn it up.
Turn up the hem at the bottom of the Jumper, and seal it with hemming mesh and an iron, and you should have it.
When it comes to doing the one with the zip up the front, then the front pattern that you create must be split right down the middle and have some extra material to fold over and attach the zip to. Make sure aswell that you leave material at the neck, so you can cut slits every cm or so and fold over to iron shut with mesh glue.
Hope thats helpful, if you didn't know it. If you did, consider me well and truely shutted-up!
