When all the pieces are ready, you will need to block them.  I usually just soak my pieces in cold water, then roll them out with a bath towel.  The towel will get the majority of the water out.

I laid out and pinned my sweater back (right side facing up) while it was still damp.

Once the back was set, I placed the front side of my sweater up against the back side so I could get it to fit together just right.  I let them dry this way for about 1 1/2 to 2 days.

I blocked the sleeves the same as the sweater body.

The front side of the sweater.  I had to fix a few tweaks on the front of the sweater by the neckline.

The back side of the sweater.

Here is Mr. Ironman bear modeling the sweater for me.