You will definitely want to look into yeast rinsing (or washing). This is a fairly simple process if you can work in sanitary conditions.
Here is a good PDF of the process by Bill Nevits. If you look on page 3, the picture of Step 5, you will see the layers of what is in the bottom of your fermentor once you get everything resuspended and settling out in a tall narrow jar. You want to siphon off the top layer and discard, this is proteins and other junk. The middle layer is the good yeast, save this. Discard the bottom layer of hop particles and break material.
I let the good layer settle out in smaller jars, then use Mr. Malty and the actual yeast slurry volume and date harvested to figure out my pitch rate. There are a lot of ways to reuse yeast, but this way will get you a consistent result and result in more consistent beers.