Setting default applications

To set the default application to open a file: select the file in a Finder window, Ctrl-Click to get the pop-up menu, click on the arrow next to 'Open With:' to show the dialogue, select the application to use from the selection box (you can use the 'other' item right at the bottom to hunt for an application that isn't on the menu). You can make this the default application for all files of that type by clicking the 'Change All' button.

To change the default Internet applications (mail client, browser) in 10.2 or earlier, open System Preferences from the Apple menu, select 'Internet' and follow the dialogue there.

For 10.3 onwards, it's a little trickier. To change the default web browser: start Safari, select 'Preferences' under the 'Safari' menu, select the 'General' tab (the leftmost item) and pull down the 'Default Web Browser' selection box. If the browser you want to use is not offered, choos the 'Select...' item and use the file dialogue to find your browser.

The procedure for choosing a mail client is broadly similar but use Mail instead.