In many dialects of SQL you can limit yourself to 10 records from the database by saying something like "SELECT ... FROM table WHERE ... LIMIT 10,20", which would return 10 records starting with the 20th.
What you want to pass from page to page of course is this offset (and update it, too - it's pretty useless if it's just 20 all the time!)
The easiest way of doing this is to add a wee bit to the URL of your "Next Page" link like:
results.php?offset=<?php print($offset+10)?>
This is only a sketch solution; in reality, you'll want a bit more control over precisely what number gets printed than just "10 more than it is now". On the last page, for example, you don't want a "Next Page" link to appear at all. And if you have a "Previous Page" link as well, "$offset-10" runs the risk of becoming negative!
In summary:
On the results.php page, you look at the value of $offset (if this is the first time the user has come to the page, $offset=0, which is exactly what you want).
Check that the $offset you get is sensible (i.e., between 0 and however many rows there are in the database). This is because anyone can type a URL and stick whatever they like in after the "offset=".
Do the SELECT and print up the results.
Put in your "Next Page" and other page-turning links in at the bottom, filling in suitable values for the offset= field in the querystring.
Hope this helps.
