Instruction:
Bikes are very diverse and have different geometries based on your riding styles. For example a road bike will have a forward leaning geometry and a mountain bike will be more upright. Furthermore you will consider the components and parts that are worth paying for. Bikes can be really expensive for features you may or may not use. Consider buying a base frame with the right geometry and then customizing parts like shocks or handlebars for your specific needs. There are many brands that carry stock frames and demoing a few will really help you understand the one that works for your body structure and application.

Response:
Local bike shops have a range of bicycle frames and parts. You can ask the knowledgable mechanic or bike groups about recommendations for the kind of riding you'd like to pursue. It's most important to find a bike that works for your body type and size. The highest end bikes won't even be enjoyable if you don't feel confident on that frame geometry.