How about some general riding tips? OK...I'm not expert but these work for me. I've been really fortunate to have some great riding pals who are awesome mentors and teachers, and to have attended some skills camps with really great coaches.
I'm not an expert or a racer, I just like to learn how to get better, because the better I get the more fun I have. These are some core concepts that have really helped me.
Look where you want to go, not at the tree/rock/edge of the trail. Looking at that thing you do not want to hit is called "target acquisition". Trust me, you do not want to acquire any of those targets, and if you look at them, you will.
Look ahead, down the trail. Where you look, your wheels will follow. Your brain will register the things on the trail in a photographic fashion; no need to think about them.
Ride light: do not have a death grip on your handlebars. You should be able to wiggle your fingers. Your arms and shoulders should be relaxed. Do not lock your elbows or hunch your shoulders. If you can't ride without locking your arms or tension in your shoulders, have the fit of your bike, specifically the stem length checked professionally.
Momentum is your friend. Momentum can get you over small obstacles, up and over rises, and around corners better than going slow and braking for everything. Too little momentum will stop you when you could just roll or hop over something.
What about a hardtail(HT) or a full-suspension (FS)? I am of the belief and experience that if you start out on a HT bike, you will learn much better bike handling skills than if you start out on a FS. Many new riders that begin on FS bikes expect the suspension to do all the work, and they don't learn how to be dynamic rider. There is no trail that cannot be ridden by one bike over the other. Just remember, it's the rider NOT the bike.
Mountain biking should be fun. If you aren't having fun, try these ideas:
find new riding partners
take a skills clinic
relax - it's not a race or a contest. Feel the sun on your back and the trail under your wheels. Just think, you could be at work, or cleaning the garage! Stop and play for a while.
get a new bike, have it tuned up, or put a new fork on the one you have
What about WSD (women specific design)? It's a great concept, geometry and frames just for women. This concept is for a specific body type: women who have a short torso and long legs. I ride a men's 15" Kona which fits me beautifully. I have a longer torso. Don't get locked into WSD, but go ahead and try it and see if it's right for you.
For some women, it's exactly what they need. Try lots of bikes until you feel the one that's right for you. Some things you can change out on your bike are smaller brake levers, shorter cranks, and more narrow handlebars.
If your LBS (Local Bike Shop) is insisting that you try WSD, or only WSD, and treating you in a condescending manner - "hey little lady, we know what you need..." Run, do not walk, to a different shop. You deserve better than that. Try lots of different bikes.
General disclaimer: this page is full of my OPINIONS. Some of my opinions are fact based, some are experience based, and some are just emotion based. Some stuff I learned from bike camps,some from friends and some things I learned off the internet!! This is what works for me. It may not work for you.
One of the reasons I'm doing this page is because of my learning style. I don't typically get things by osmosis, or even by watching someone. I need things explained, broken down and demonstrated. Then I like to practice the skill and and apply it. My goal is to get comfortable enough with a skill that I don't have to think about it anymore; the muscle memory and repetition kicks in. If this is not your learning style, then this page may not be for you. Thinking too much is bad, but some of us have to think and process to learn, and then disengage the thinking part as we get more comfortable with things. Thanks to everyone who has contributed, directly or indirectly. (update 2/06)