How do I start a cover letter if I'm not applying for any specific job?

YOU DONT!!! I have 15 employees now and if they couldn't take the time to write me a custom cover letter then I cant take the time to see them.

Sometimes this may a be a good reason not to have a cover letter. Usually the purpose of a cover letter is to provide a specific reason why you would be a good fit for the position. If there is not any position in particular for which you are applying, you may not want to include one. The other option is if you do decide to include one, think of specific skills or experiences that perhaps highlight some great examples of your career. Based on the industries of the companies where you may be sharing your resume, try to pick some specific examples that at a minimum relate to these industries. Another option is to think of the types of positions you may qualify for. If you were to give me your resume, what positions do you think I might consider you for based on what I see on your resume? This may help you brainstorm some ideas to think of specific skills or talents that set you apart from others or that give a very good picture of what you bring to the table. Since it is part-time work you are seeking, think of the most common part-time roles that are available in your area, and again relate your cover letter to those types of roles so that the employer can see those specific skills from the beginning. I've included a source here that may help with the writing of the cover letter, and though it talks about the advantages of being specific, it may help you in preparing this.

The answer to the question you're asking is To Whom It May Concern. Or Dear Sir/Madam. However, I would advise against sending mass mailings. Instead, research the places where you would actually want to work, find out why you'd like to work there and who is the hiring manager, and then write targeted letters to those specific people. If possible, even visit those places, talk to the employees there, and maybe even the hiring manager. Introduce yourself, and say why you're interested in working there. You're much more likely to get a job that way, and especially much more likely to get a job you enjoy. Good luck! Elisabeth

Serious job seekers typically create a draft cover letter. Whereas, the bulk is about them and it serves as a template. Then, as they channel there directions, simply fill in the contact info and possibly the first couple lines. For a "general" cover letter, simply address the H.R. Manager... Best of in your quest...