Hi,

The UniPager control properties, configuration and usage is thoroughly described at Controls Reference - UniPager article and following in the section - namely, UniPager styling and appearance.

If you're using Portal engine development approach, you could also check the general scenario using DataSource, Filter, Listing webpart and the UniPager (that will count the items in the datasource automatically) shown in DevGuide - Using DataSource webpart

Should you need any additional details, please feel free to ask.

Regards,
Zdenek