What quality hard tails worth looking at?
If you're willing to buy used you can get some great deals. Even that one that Costco sells isn't bad. You Know rides one, and for the price, they're hard to beat. I recommend one with disc brakes. $300-500 can get you a really good hardtail. Lots of people want full-suspensions, so hardtails are getting even cheaper.
If I were you, I'd go into Canyon Bicycles and get sized up. All of their bikes will be a lot more $ than a used bike, but you can learn about bikes and what to look for. Be straight up and tell them "I'm looking to get into mountain biking. I want a used bike, but I don't know the first thing about them. Can you teach me what to look for and how to size a bike?" Bike size is the BIGGEST factor, in my mind. If you get the wrong size, it'll be tough to gain confidence and control over your bike. I'd guess you'd want a LARGE, or 18-19" bike, but don't go off my guess, go off your sizing. As a general rule of thumb, you should be able to stand with your feet flat on the floor, and with the seat completely behind your butt, lift the bike until the tires are a good 2-3" above the ground with the frame hitting your pelvic bone.
There's a lot of debate around 26" vs 650b vs 29" wheels. Everyone has their opinion, here's mine:
- If you're wanting to carve berms and hit jumps and ride aggressively, the 26" wheel bikes are the preference.
- If you're wanting to do long climbs, generally slower speeds and you're more worried about being as efficient as possible, a 29" wheel is a great choice.
- If you want to overpay and be hip on the latest trend with limited tire sizes and parts, and have a mix of the benefits of both the 26" and 19" (so they say), the 650b (27.5") is for you.
I ride a 26" bike and I love it. The 29ers climb really well, but I can't ride them as aggressively as I like, and they hold me back on the downhills. Plus I don't feel comfortable with my COG so high. For your first bike, it doesn't really matter whether you ride a 26" or 29", it's all going to feel a little weird.
One more option is to rent a few different bikes to see what you like. I think you're on the right track with the hardtail though, it will make you a better rider once you switch to a full susp.
Confused yet?