You can also reference part I and part II.
Two of my biggest questions when I started were:
"How fast should I be going on my bike?" and "How fast is fast?"
A general guide to speed is this:
Depending on the bike you have "good" speeds will be different. My current average is 14.5 mph on my road bike, but the hybrid is still 13. A mountain bike would be lower. My advice is to figure out your natural speed right now. If your average is 10 mph with out pushing that's exactly where I started. How do you get faster?
Your speed will increase on its own. The more you go out, the stronger you will get, the better your cardio will be and the faster will you get. Apps like Strava help me to push myself. Strava lets you make segments or ride segments that are already there. I segmented my whole route and started working on one segment at a time. That way I only pushed myself hard for a pre set length. one by one I became Queen of the Mountain or moved up spots. Then, after a while, I was beating records without trying. If you are pushing hard to raise your MPH average I also suggest angry music. I ride much faster when I am wearing my ipod and it is set to angry. That was my route to going faster and it is what I would suggest to you.
The next big question:
How far should I be biking?
Most people can bike 10 miles at their current fitness level. I started a 6. The rule of thumb is to increase your miles 10% every week. For example:
Week 1 10.00
Week 2 11.00
Week 3 12.10
Week 4 13.31
Week 5 14.64
Week 6 16.11
Week 7 17.72
Week 8 19.49
Week 9 21.44
Week 10 23.58
I did not follow this in the beginning. My goal was to go 1 mile more every bike ride and I went out three times a week. I did that until I was averaging 50 miles a week. Now I am in week two of a century training plan ( you can see it here) and I am more closely following the 10% rule. You should do what feels right for you.
This is where the bike computer that was discussed in Part II comes in handy. You can't increase your miles very easily with out knowing how far you are going. Map My Ride is also a good tool for figuring out distance and elevation.
Part 4, everything you ever wanted to know about pedals, here!