Submitting...the publishing kind

Write the entire first draft. 

While polishing up that first draft, get a subscription to Publisher's Marketplace. Make a list of agents/editors who are selling/buying a manuscript similar to yours. 

When your manuscript is ready to be ready, start querying. You can get agent/editor submission information from Publisher's Marketplace. Agentquery.com is a good source for agent information.

Keep track of the queries. I use 3x5 cards because they are big enough and small enough.

Send the submissions. Keep track of those as well. Include what you sent, etc. At the time you send them, you may think you would never forget, but consider the possibility that you will forget. There is a good chance you will want the information later. For example, what if you want to query that same person again in the future? In that case, it would be good to know what you had sent before.

Start working on something else. It will make the waiting easier.

For a bit more, visit my other site: Adventures in MFALand.  Use the tag "publishing."