I am new to cycling and I was wondering if there are some tips to improve my time and speed. I am kind of learning my gears but any help would be appreciated. I can go about 18 miles in about 1.5 hours. I would like to set a pace at about 20 mph and work up to 30 miles, maybe more. I can probably do about 12/13 mph. I have a mountain bike for the moment, I bought it years ago its still in great condition since I havent used it much. Also any opinions on the indoor trainers for bikes where you bring your bike inside(not sure of the exact name) but not the bikes they have at gyms.
Ideally I would like to bike to work and thats 13 miles (by car) and would like to do that in 30/35 minutes and its against the wind. I would like to work up my miles so I can do some charity races next summer and push myself.
Any help would be greatly apprecitated.