Mr. Lukeman is a Literary Agent based in Brooklyn, NY. In The First Five Pages, Mr. Lukeman provides a wealth of useful information for writers--particularly for those writers who are trying to get their first book deal.
A book publishing truism: Agents reject 99% of what they're sent. Publishers reject 96% of what Agents submit. Getting a bona-fide book deal--one where the publisher pays you an advance and royalties--is very difficult. Hundreds of book deals are made each year. Hundreds of thousands of writers compete for them!
The First Five Pages will help you avoid giving agents and editors any easy reasons to say "no" to your manuscript.
I highly recommend reading (and applying) The First Five Pages to your writing before you submit your work to agents or editors.
Look up Lukeman on Amazon, he's written some other good books too. He's one of the best resources for writers today.