There are some knitters out there who never block anything they knit, no matter what the pattern says. Yes, you can get away with that a lot of the time. Many patterns call for blocking before assembling a sweater, so the pieces fit together perfectly when it comes time for sewing the seams.
Then again, some people never knit anything that really needs blocking, like a ski hat or baby booties. But, for the most part, blocking is a good idea and it makes the project look more professional.
By blocking what you knit, you can actually mold the article into the shape you want, or the shape it should be. This is especially true with those stretchy natural fibers, more than with acrylic projects.
There are tools you can buy, like rustproof blocking wires and T-pins. Mats, clips and sock blocking forms can be purchased as well. However, you can usually get away with a simple box of straight pins.
There are three common ways to block your piece of work: Wet-blocking, steam-blocking and pin and spray blocking. All involve pinning the knitted piece down onto a towel or mat and laying it out on a flat surface where it will sit for a couple days. Make sure you chose a location where the pinned item will not be disturbed.
When you wet-block, you wet the knit material in cold water. Gently squeeze the water out by rolling it up in a dry towel because you must never, ever, EVER wring out wool. It will definitely become very stretched out and might even begin to felt. Once the excess water has been removed, you can lay out the piece and pin it down into the proper dimensions.
Steam-blocking involves pinning down the piece before wetting it. Get an old pillowcase or similar item, wet it and wring it out. Press the pillowcase on top of the pinned item allowing the steam to go through the pillowcase and into the knitted project. Keep ironing until the pillowcase is dry. Then allow the knitted piece to dry.
If, due to the delicate nature of the yarn, you are afraid to use either of the first two methods, try pin and spray blocking. In this method you pin down the knitted piece while dry. After it is in place, you spritz it with a spray bottle of water in order to get the material damp and flexible.
However you block your wool project, be gentle with it, especially when it is damp. It might smell a bit like a wet dog, but in the end you will have a professional looking piece that will leave you beaming with pride.