The Best Entry Level Jobs for Aspiring Writers

Are there certain entry-level jobs, besides a writer's assistant position, that are more helpful to writers than other entry-level jobs?

I believe the best entry-level job for an aspiring writer is an assistant position on a show.  Working at an agency/studio/network/production company, etc., is also beneficial, but working on a show provides writers with direct connections to other writers and producers -- the people who will ultimately hire them on staff.  If you have the choice between working at a network or working on show, whether it be an office PA, set PA, or EP assistant position, choose the show. 

That said, network assistants often make more money than first time PAs [approx. $700 versus $550].  If you feel you need to take the job that pays more money, take the network job.  You won't be tanking your career.  There are countless ways to break into the industry, and there are many many working writers who began their careers as network or studio assistants.  Each person must make their own path.