Follow my list of do's and don't for cleaning your cast iron after use. This will keep your pan in excellent condition for years to come.
Seasoning enables cast iron cookware to be rust-proofed, creates a reasonably good non-stick cooking surface, and gives your pan that deep black color normally imparted by regular usage.
I describe the three stages of restoring your pan: stripping, de-rusting and seasoning.
These pages are high level summaries for cleaning, seasoning and restoring cast iron cookware. If you really want to get into details and the science behind preserving cast iron, I highly recommend following my links to
The Cast Iron Collector.