My question is concerning how the Apple Developer program works. I am not yet signed up to submit apps to the App Store, so I was wondering how the process works. Are apps submitted through their website with an interface? How do the taxes/rates work? How often can you submit updates, or update the info for the app?
When you purchase iDP, first of all you will fill Banking info, Contact info and etc.
Then using iPhone Developer Portal you have enter your iPod/iPhone id and create 2 types of certificates - for Developing and Testing and for Distribution. You will also have to create Provisioning Profiles - they will make you able to test your app on your own iPhone/iPod Touch.
When your are ready to submit you app, you have to compile it using distribution certificate, and compress it into usual ZIP archive.
Then using itunesconnect.apple.com you can submit your Applications. It is quite easy - just fill form, upload screenshots and binary file, select category and price (30% eates Apple, 70% - yours). You can submit updates as often as you can, but every update will be reviewed by Apple engineers, usually it is from 10 to 14 days.