Automate your Mac
The first thing to do is to make your Mac turn on by itself. You can set it to do this in the Energy Saver preference pane in System Preferences. Just load it up and click "schedule" and choose a time to start up (and/or shutdown) and on which days you want this. This will also wake up your Mac if it is asleep, but this might not work if you have a password enabled screensaver.
As far a scheduling specific applications goes, you have to use applescripts or automator actions for most of them. If you aren't completely super lazy, it is pretty straightforward to create a workflow in automator that opens up a list of websites, or starts an iTunes playlist going. To get this worklow to be carried out at a certain time, create an event in iCal and set an alarm. As the alarm action, set it to open up the automator file.
However, in some applications you can get the same results without making workflows or scripts. For example, in Firefox you can set multiple websites as your homepage, and all of these will open up when you start Firefox. There are two ways to do this. The first is to create a folder of bookmarks with all the sites you want to load on startup. After creating this folder, go to the Firefox preferences and click "use bookmark" to select the folder. The alternative way is to type in each address into the homepage field with a | (pipe) in between. Be sure to set Firefox to load your homepage on startup using the dropdown menu.
Finally, some applications have built in scheduling capabilities. Microsoft Entourage has tools to set Send and receive schedules that check for email at certain times and Apple's Backup has its own scheduling feature to carry out automatic backups however frequently you want.
You can use all of these features to automate your Mac and make sure that you never have to carry out a tedious task again.