I would not create fake accounts to make it look as if the site is populated as that can backfire on you in too many ways.
Unless you are very skilled at creating content that looks like it is from different people you may find that your users will be able to spot the fake accounts. Always remember that humans are pattern-seeking mammals and if the written content uses the same turns of phrase or the artistic content has an easily identifiable hand then the users will see it and know that the content is faked. That may hurt you far more in the long run than being patient and waiting for the UGC to happen hurts in the short run.
I would start small and personal. Approach friends and family you think may be able to help with initial content generation. Join a usergroup or a meetup and pitch/recruit there. Get a small but loyal cadre of users and don't worry about the bigger picture for the first little bit.
Once you have some content generation, you should begin to increase the radius of your visible marketing. Do some dead-tree posting on local bulletin boards, ramp up the presence on Twitter and Facebook (and, if appropriate, LinkedIn, Pinterest, etc) maybe even promote a few FB posts for $20 to get some extra exposure. Become a frequent commenter in communities that match interests with your site and recruit like-minded individuals.
Make sure your signup process is fast and painless for the user. The entire experience has to be as low-friction as possible to compensate for the initial lack of value. Try to do as much support as you can so your community knows its founder is engaged and active.
All of these are small steps but can help add and retain early adopters. Once you have enough to reach a critical mass you'll be able to ease up on recruitment and retention aspects.