For the original poster.....
Go out and buy yourself a computer with a cadence function.This will help you quickly guage your pedal rpms.
So forget about how fast you can go on your bike for now, just focus on your cadence.
Next, get yerself a good heart rate monitor, and get to know the different ranges of heart rates and what they mean. Work them.
If you learn to focus on these two numbers, and learn to 'ride' them...I guarantee that it will make you a better rider quickly....everything else will be relative to these two measurements.....and that includes GEAR CHOICE and the foods that will fuel your engine.
"One day in the future, you'll be biking long, and all of sudden take notice of your legs smoothly pumping away. You'll suddenly be amazed at how relaxed your breathing is, barely putting up a sweat, as if your legs were a part of the bike and not yours. Painless.
Looking around you'll see that your with the lead pack in today's club ride...taking turns drafting with the three fastest riders. Today they take notice.
The best part is how you feel....NOTHING, but the coolness of the wind, and you'll be startled when you see your bike computer is showing 28 mph. The asphalt a blurr as it quickly moves underneath you.....truly mezmorizing
I've been there....it's an awesome state of being.....but it takes work. I did it on a $400 bike, the rest was blood, sweat, tears, and a love for riding.... ;-) Don't expect to much off the starting line. You'll get there eventually, just make sure your having fun all the way, and like a metaphor for LIFE, you'll soon realize it's too short of a ride" - JE