Use the Writers and Artists Yearbook for finding publishers and agents.
Saves a great deal of time. Will give details of who does what. Many useful articles in it. Does not list vanity agents or those who say they may charge for publishing. Also keep as up to date copy as you can as jobs change in publishing very quickly.
Study writing blogs
Like Time to Write and Patsy Collins' website/blog. Loads of tips on what to avoid doing and what publishers/agents want. Also in Patsy Collins' case, lots of writing competition details, always useful. Good, entertaining read too! Try to have a variety of those written by authors, editors, those working in publishing as you get a variety of perspectives then.
Study professional writing magazines
Mslexia, Writers’ News/Writing Magazine etc. Again learning about the industry can only help you. A lot of the writing magazines run free or cheap to enter competitions. Listings or winnings there add to your writers’ CV and will give you something to show publishers/agents.
Read, read, read
You’ve got to know what you like to know what you want to write. You’ve also got to know what you don’t like so you know what to avoid or what you think you can do better than (that can be an excellent spur). Equally don’t let reading brilliant, inspiring fiction make you downhearted. Let that inspire you to be as equally brilliant even if it does take you 50 years!