Hi Jennifer
I think it depends on your business, however try to commit to at least fifteen minutes to an hour every day. Be consistent & persistent.
What I would do is make a list & sign up to the following:
*Facebook Personal Profile (for liking other pages)
*Facebook Page (for your Business and where you will post information about your industry, start discussions, etc)
*Twitter - similar to your posts on your Facebook Page but obviously limited to 140 characters
*Hootsuite - Allows you to create one post and distribute it to multiple social media accounts
*Linkedin - don't just post your resume, participate in Linkedin Groups related to your potential customers, and also Linkedin Answers and answer questions where you can add value, not just about VAing but anything you have knowledge on
*Forums - such as this one but you should also look for small business forums as that is where your likely customers are going to be
*Blogs that rank highly for your keywords - Presuming your website has been optimised for search engines (if not you should look into it, I have written an article on it at my website -
http://www.smallbusinesswizardry.com...ine-marketing/) look for blogs that rank highly for the keywords your website is optimised for and eave comments on the blog that add value to the discussion.
This may seem like an extensive list but you don't have to do all of them every day. Try and do at least something every day to get in the habit. You will learn more as you go.
Best of luck with your business