Depending on what Database engine you are using, you will need to restrict the number of records returned. In MySQL this is done by adding a limit command to the SQL i.e.
SELECT Surname, Forename FROM users LIMIT 100;
You can then add more to the command to instruct MySQL to return 100 rows starting from a certain record i.e.
SELECT Surname, Forename FROM users LIMIT 300,100
In this example the result will start at record 301 and return 100 records. Therefore the link 'next' that you mention should state the record to begin at and then include this within the SQL being used.