Anyone who wants to become a literary editor, more commonly referred to as a book editor, will generally need to work his or her way up within a company. Most individuals begin as copy editors or editorial assistants before they can even think about becoming actual editors, who not only edit material for content, but also constantly work to acquire new material for the publishing house for whom they work. Many people in this field begin by getting a college degree in English, typically with a focus on literature or creative writing; sometimes, candidates for this position will also go on to earn a master's degree in publishing, but this is not an absolute.
Unfortunately, there are many, many people out there who want to become a literary editor as much as you do, making it a bit more difficult of a field to get into. Once you have a bachelor's degree, if you choose to pursue that educational path, it will be very likely that you'll need to freelance for a while. Local magazines or community newspapers represent great opportunities for this, and will give you experience as well as help you to develop and improve your copy editing skills.
When you are trying to become a literary editor, you may also want to determine if there is a specific genre you want to work in. You may not always get this choice, but coming into any publishing house with an existing specialty will generally make you more appealing, and it will also help to guide your job search in the first place. When you begin applying for actual positions at publishing companies, it will generally be necessary to start from the bottom and work your way up. For many publishers, an editorial assistant is the most entry level job they have for which they will actually hire a staff member, and not a freelancer.
It is necessary for anyone who wants to become a literary editor to have a love of reading as well as strong knowledge of grammatical rules, language use, and all other aspects of good literature. In addition to these skills, however, most upper level editors will work directly with authors to acquire new manuscripts as well. They will need to have a good eye for the type of content the publishing house looks for, as well as the ability to develop long-lasting relationships with authors. As you are attempting to become a literary editor, it is important to regularly demonstrate all these skills.