This link is great. I wish I had this when I made my husband's first "Sherpa hat" I made some little dancing men and they ended up looking like they all needed to go on a diet!
This is from a web site call The ABC's of knitting. It has all kinds of info, from Japanese patterns, to how to's for the basic things. Lots of projects, and links also.
If you need to convert a picture, logo, etc. into a knitting pattern this is great free software.
From the software info....
kpghttp://sourceforge.net/projects/kpg/ is a free program that can create knitting patterns out of pictures. It can either create straight patterns or illusion patterns that only reveal the picture when viewed at an angle.
The knitting patterns are simple rectangles (squares) that use simple stiches, a regular "knit stitch" and optionally a "perl stitch". The patterns can be used to create large blankets or many smaller patch-work squares suitable for making a large knitted piece. Experienced knitters are able to take the simple square knitting patterns and integrate them into more complex pieces such as jumpers/sweaters.
kpg can take any kind of bitmap image and create a knitting pattern. It is recommended that low colour images/pictures be used to ensure the knitting process is as simple as possible. It is possible to use a black and white picture and create a pattern using only one colour and using different stitches for the picture. Examples below.
kpg http://sourceforge.net/projects/kpg/ is the only free open source tool I know of to create knitting patterns. Essentially a png2knitting_pattern converter. In theory the patterns kpg generates could be used for crochet (with minor modification).
It is amazing what is available to us online!