From the LyX Documentation [Link]:

To administrate BibTeX-database files you need an editor, or more comfortable, a so called BibTeX-manager. Here are some links to BibTeX-managers:

• BibEdt: Open source minimal BibTeX editor for Windows.

• BibTexMng: BibTeX editor for Windows, commercial, test version limited to 50 database entries.

• Bibwiki: Bibwiki is an extension for MediaWiki to manage BibTeX bibliographies. With Bibwiki it’s easy to import records from various sources, manage digital documents, export lists of references via BibTeX and create lists of references in Wiki articles.

• JabRef: runs on all platforms, requires a Java-runtime environment.

• Mendeley: runs on various platforms and also has a web interface, exports to BibTeX.

• Pybliographer Bibliography manager for Gnome. Runs under Linux and other Unix-like operating systems. Command-line version runs on Windows.

• refbase: web-based reference manager which can import and export BibTeX.

• tkbibtex: BibTeX editor written in TCL/TK, runs on all platforms.

• WibTeX: BibTeX editor for Windows, can also work together with MS Word.

In my case, I have installed JabRef and it is very complete, professional, and easy to use. It also has some interfacing functionalities with LyX and other editors.