All HOWTOs and other LDP documents are copyright by the authors so the LDP doesn't have any special rights to your writing. We only accept documents that have a license which permits anyone to copy and distribute the document. We encourage authors to also allow modification in their license. This way, if the author stops maintaining a document, someone else can do so. For more details see our Manifesto.
If you are not sure what to write about, take look at some of LDP's documents, including the ones in Unmaintained HOWTOs. Also you may find topics that you are interested in that are not adequately covered by existing documentation. If you find something already written and maintained that seems to need improvement, try to contact the author.