sooperb said:
I have googled, there is lots of information out there
Funny though, I came across a link to a site I found last year, the guy was a real cycle buff and came across as a really nice chap. I spent the best part of an afternoon reading archives and exploring his site. When I tried to find the latest entry, I was gutted to discover that he had died earlier in the year. His name was Sheldon "Shifty" Brown, I don't know if I am allowed to post a link but here goes:
http://www.sheldonbrown.com/home.html
I really admired him, his ethics and the fact that he was a real family man too. I felt a real sense of loss, surprising as I had only just found his site. He really he knew his stuff, the site is still there with all the links, advice, technical stuff and photo gallery, really worth a look.
Hi Sooperb, glad to see you found and enjoyed Sheldon. He is generally very highly revered round these parts, and is often quoted as a source of wisdom.
For what it's worth, with your gearing question, I'll explain how I generally work it. I'm on a mountain bike with 24 gears (3 front x 8 back) so my situation might not directly match yours (the ratios are bound to be different in any case) but it might give you a bit of help.
So I will usually start off with the left hand on 2, right hand on 3 or 4. Those are comfortable starting gears for me and enable me to get to a reasonable speed before I feel the need to shift. For most normal flattish riding, I tend to leave the left on 2, and run between 3 and 6 on the right.
If 2-6 feels too light (normally if I'm going slightly downhill or have a tailwind) I'll either go to 2-7 (if I can see it won't be for long) or shift up onto 3 on the left hand: big ring at the front, and then use 6, 7 and 8 at the back.
For hills, or if 2-3 is too much of a "grind", I'll drop the left hand down to 1 (small ring at the front), and then use 1-4 at the back.
One thing you'll notice is that I tend to use a limited range on the right hand, depending on what I'm using on the left; so with 1 on the left, I run 1-4 at the right, 2 on the left gives me 3-7 at the right and 3 on the left I limit myself to 6-8 at the right.
This is to avoid "cross chaining": having the chain going too far across the blocks of gears puts extra stress on it and can wear it out quicker.
There's no real right or wrong way to do it - so long as you avoid cross chaining - but the idea is to use the gears to keep your legs going round at a speed that's comfortable for you. Turning the pedals fast in a low(er) gear is often called "spinning", pushing a high, heavy gear is known as "grinding". The former is, I think, good for working out your heart and lungs, the latter is good for strengthening your legs. You're generally recommended to be running at about 80-100 rpm at the pedals, but some are more comfortable outside that range. I tend to naturally work at about 90-95 rpm.