I would say look at your SQL SELECT() statement. You can use the LIMIT clause to bring in a range of rows. LIMIT 5 will bring the first 5 rows. LIMIT 0,5 will do the same as the first number is the row offset with the first row being 0. You could save the offset into your search form and increment the offset by the range each time the page is called.

Here is the MYSQL4 SELECT documentation.

Enjoy

Keith