How to create a button with a icon inside ?

Can someone show me a example ? I'm doing some refinements in an database-oriented app, and show database navigation and action buttons with small icons instead of text will do a lot for the visual - and cuts a lot in internationalization too ! If isn't ask for too much, a example of a combined icon+text button too will be great too - some not-so-obvious actions, like data integrity check need a text anyway. Know how to make this will simplify my work a lot, not to mention the visual aspect. Thanks !