There are many things to consider. I think hops are likely to stay desirable to brewers for a while. Price depends on how well the big growing areas do each season and a few other factors.
How you would go about growing depends on where you live, your soil, sunlight, water, etc. The same stuff all growers need to think about.
Some of the more popular varieties are proprietary right now. You maybe need to enter into an agreement to grow and sell them.
Do much research online. Contact other growers. I know in Michigan there is a group dedicated to expanding the hop growing industry in the state. The Michigan Hop Alliance helps growers share information, equipment, and other things in order to encourage growing. The west part of the state has a good climate and soil for growing hops due to Lake Michigan.