Hey mate, I have a few bikes, a couple of hardtail mtb's and a fixed gear roadie. The best advice I can give is go to a few bike shops and sit on the bikes in your price range. For $500 I would steer clear of dual suspension, they components are generally too cheap to last very long, especially if it will see any time on dirt. You should be able to get a reasonable hard tail for the $500-700, I would stick with the bigger brands (Giant, Kona, Mongoose, etc) as you will have the backing and support of at least a 12 month warranty. At this level frames are much of a muchness, all fairly adequate for exercise and the occasional trail. Where they differ is in groupsets (shifters, derailleurs, brakes, etc) and forks. generally they are all a compromise but you can get some decent stuff. I have a 2008 Giant Yukon that has done about 2000 km's on all kinds of terrain, from the You Yangs to the street, and has held up fairly well. Chances are if you enjoy it you will end up upgrading the forks and groupset, so if you can find a bike with a decent frame it will be an advantage, or at least a frame that is compatible with the bikes higher up in the product line, as you will be able to match parts easier later on. Also, try to get a mountain or cross country style bike rather than a dirt jumping or park bike, they tend to look cooler but alot a single speed/or 9 speed and not very practical for the type of riding your talking about. If you need any specific advise I would be happy to help, or even pro's and con's on specific bikes you are looking at. Cheers, Daniel. Edit: After having a quick look on bike exchange this is the sort of thing I would be looking at, last years model significantly reduced, name brand group set and forks, this model yukon also has hydraulic brakes, although I would think you would be looking for a medium size frame and this runout price is for xs, s and xxl. http://www.bikeexchange.com.au/bicycles/giant/mountain/giant-yukon-mountain-bike/ivanhoe/vic/100134430 Gives you an idea, also a little outside your price range...