Module done, now I want a nightly report emailed out

Hi everyone. I'm new to developing in Drupal and I was excited to complete my first module recently, including setting up database tables during installation, a nice UI for an agent to look-up information, etc. All *very* basic stuff for anyone who has done it, but a big lesson for me. It was a lot of fun.

OK. Now I'd like to have a periodic report go out based on entries in the database. If there are new entries, I'd like to pull together the tables and fields I want, export it to an XML or CSV file, and then email it.

Here are my questions:

• Does this sound like a cron job I should create?
• What language should I write this in? (i.e. C? PHP? something else?)
• How do I "call" it? (I'm guessing this is back to learning more about cron)

I'm sure like my first module this is very basic stuff for you folks, but I'm just trying to figure out what path to go down. I started down the PHP path (didn't get too far yet) and started wondering if it would be better to have a cron job call a C program to do the data pull and writing and then a shell script to mail it? You can see I'm clueless here.

I realize there are many ways to do things, but I'd appreciate an experienced opinion on how I should go about this.

Thank you everyone.
Tom