If you are interested in scheduling tasks as a normal user account in Ubuntu (i.e. you're not doing system-wide things as root), then you should skip all the specifics of
Instead, look at the Scheduled Tasks application available in Ubuntu via the Unity Dash or similar applications menu. It vastly simplifiies the work of scheduling items. There are some "gotchas" related to its use, but this way you don't have to do anything in the command line.
For example, I have a little backup script that I run periodically using Scheduled Tasks. (The program basically inserts items into your crontab, etc.)
Scheduled Tasks provides two different views. One view is simplified, like this:
The other view shows what the crontab would show:
One of the "gotchas" is that your normal "PATH" is not available for a specific scheduled item, so you need to be explicit about what command is to be run.
Anyway, the details of
anacron are all a bit too broad to be Ubuntu-specific.