Quoted:
I have an external hard drive that has about 1TB of movies. Most of those are in .avi format. I also have some DvD's, (standard format and also some Blue Ray). Does anyone know of an application that will allow me to convert to MP4 and let me rip the movies from disk? What I want to do is put them on my iPad so I can watch them during down time at work.
DVDFab is good for ripping DVDs and Blu-rays to the hard drive. Then, you'll need to convert them. Install Handbrake and Vidcoder. Handbrake by itself does pretty well with DVD resolutions. For HD resolutions, use Vidcoder (which uses the Handbrake engine). Encode some short segments first, until you find the right combination of quality and size. Then you can queue them up and start encoding.
If you want to get extra fancy, you can download MetaX, which will let you tag the videos, add descriptions, ratings, etc.
Unless you've got a beastly CPU with lots of cores, plan on a while to encode HD videos.