I’m a mid-core mountain biker, as opposed to hard-core. Did a 20 mile bike race last summer, that was the height of my mountain biking hardcoreness.
Here’s my two cents:
1 - comfortwise: Take any seat that comes with the bike, and throw it away. Go buy a cushy women’s seat, with the cut out in the middle. It’ll run you about $30 for a decent one. Trust me on this - the seats that come with a bike are #1, not that great, and #2, designed for men. If your wife wants comfort, BUY A CUSHY WOMAN’S SEAT. Also, buy her a pair of padded bike shorts. It’ll help a lot.
2 - Price. I don’t know what you can get for $300, but I can tell you a couple things about buying a bike. For what you describe, she doesn’t need full suspension. The only riders who need full suspension are the ones who will be doing hardcore technical rides. I don’t have a full suspension bike, and neither does Mr. Athena, who does his fair share of technical type stuff. Mrs. Smoke doesn’t need one. Heck, she doesn’t even need front suspension, but if you can afford it, get it.
If it’s a choice between a good bike without any suspension, and a lower end bike with suspension, get the good bike with no suspension. I’m pretty sure you can get a good starter bike for $400-$500, and maybe even cheaper. Shop around.
Buy your bike from a bike shop, not a mass merchandiser or someplace like Target. A good shop will explain a ton of stuff to you. Go visit a couple bike shops, and get a feel for the people working there. Look at the used bikes - often they’ll have refurbs that will do you just fine. If you buy a good, solid name brand bike, if your wife doesn’t use it, you can sell it. If you buy the Huffy on sale down at Walmart, good luck selling it, much less riding it.
One way to tell a good bike shop - a reputable shop will include something like a “30 day tune up” free with the cost of the bike. At least they do out here, in Colorado. Some even offer free tune ups for the life of the bike. At the very least, you want someone to go over the bike after 30 days of semi-regular riding. Bikes settle, things get loose, things need to be oiled. A good bike shop realizes this, and tries to encourage their customers to do it by throwing it in free.
3 - Ease of use. If you buy a bike from a reputable bike shop, the bike should be a good one. If you buy that Huffy, forget it. The other major issue that has a lot to do with ease of use/comfort is the fit of the bike. It’s gonna be hard to fit the bike to your wife unless she’s there. The best way to buy a bike is to go in and ride one for a while. Fit is extremely important - when you straddle the bike, the top bar should be about an inch or so from your groin. When you’re riding and the pedal is all the way down, your leg should be slightly bent. If you really, really want this to be a surprise for your wife, make sure that you can trade the bike in if it doesn’t fit well. Better yet, find a good bike shop, and surprise her a few days before Christmas by bringing her in and getting her fit for a bike.
Brands to check out: Trek, Specialized, Giant
Any other questions?