I'm going to start trying to practice about 3-4 hours a day, and I need some help.

What are some good exercises that will help me with speed and accuracy (both fretting and picking)?

I also want to improve on pinch and artificial harmonics.

I'm not trying to learn how to "shred." I just want to play better. I mainly play Thrash metal.

I know there are good video lessons on Youtube, but I'm one of the 20 people who still have dial-up but go ahead and post a link to one if you want.

Also, what are some good DVDs or programs for improving?
Speed and accuracy are just muscle memory techniques. Once you learn what you need to play, you just play faster and it'll be accurate (hopefully)
Live as a man. Die as a man. Become a man.

That's the proof of your incompetence, right there.
You lack the qualifications to exercise free will.
For exercises do 1-2-3-4 on every string then 2-3-4-5 on every string and so on through the whole neck. I have heard that john petrucci's instructional video "Rock Discipline" is good.
Try and find Steve Vai's ten hour workout somewhere (You don't have to spend ten hours on it though!)

Practice SLOWLY with a metronome to start with, and I guarantee your accuracy will improve hugely.