Each entrepreneur has their own process at developing concepts, however there are (or should be) repeatable steps in each and perhaps overlap in some areas with the processes of others.

My Steps Process 1:

1. Identify a gap in the marketplace (any product or industry is ripe for discoveries)
2. How large of a market is the gap I've identified (customer size or monetary value)
3. Develop Initial concept (paper, digital or physical)
4. Collect feedback from potential customer (survey, watch them use it, etc.)
5. Evaluate results, if positive continue and refine, if negative review and determine if worth refining

My Steps Process 2:

1. I have a great idea (I think)
2. Explore the idea to expand opportunity / use cases
3. Look at the market to see if it fits into a gap
4. If there isn't a gap, what is the competition doing right and wrong
5. If opportunity seems viable create initial concept (step 3 in Process 1)
6. Collect feedback from potential users (step 4 in Process 1)
7. Evaluate results (step 5 in Process 1)

To development team you need the following, people you trust and vendors you trust.

You should tap your existing networks (professional and social) to secure talent or leads. You can use past experience or your network to point you in the right direction for trustworthy vendors.

After that you essentially repeat the process (not necessarily mine) but whatever process you used personally and expand it to your entire team.