[eluser]StevenSokulski[/eluser]
Radou
There are a handful of good "Build a blog in 20 minutes" type posts out there that should help you to understand the basic principles of CodeIgniter including form validation, database interaction, etc. Beyond that, the manual is fantastic.
I was in your shoes not that long ago. Maybe 18 months? If you've got a decent understanding of PHP and can put together your data model, you should find that CodeIgniter is a really great extension of your workflow.
And if you have specific questions, post 'em in the forum!