I see you have a very good traffic on your blog and high PR and high number of inbound links which is the things most people look for when searching for guest post opportunities. You shouldn’t have any problems finding guest posters on MBG.
Ok MyBlogGuest first: You should use "gallery" options on MyBlogGuest. Writers publish their articles in gallery and you can check (daily) if some of the articles there are suitable for your blog. If you like some of the blogs you apply for that article and than writer decides if he likes your blog to publish his article on your blog.
Make sure when you apply for some article over there to put these facts in comment box. Write one or two sentences about how your blog is very visited and has a good authority, PR and inbound links especially Linking Root Domains. You can use Open Site Explorer to check number of Linking Root Domains (that's the number of websites that link to your website, one of the strongest SEO factors).
Also, if possible, write in comment box how you will publish the post immediately or in a day or two because majority of people are are SEO's.
SEO ‘s come to MyBlogGuest with many articles and they want them published as soon as possible.
Use forums there. You can open a thread over there saying how you need guest posters, and, again, write couple of sentences about your blog over there too. Same things I already mentioned, so that people can see your blog is a great opportunity for their articles.
Also mention how you will share articles on social networks, Facebook, Twitter itd.. You can mention yourself on those networks how you are looking for guest posters for your blog.
One more thing, I see you don’t have comments on your blog, make sure you add those. They became very important now with rel=author thing and with building authority for authors. More good comments and on subject you have on your blog, better your articles will be ranked.
Mention on a homepage that you are looking for guest posters. Search around on Google which queries people use to find Guest post opportunuities. From my own experience you should do at least these 3 things.
Put a tab in your navigational menu saying “write for us” and also on your blog post page add one more sentence in right sidebar saying “we are accepting guest posts now”.
Make that visible for your visitors. Also make a separate page and call it guest post guidelines, where you will explain what you expect from people how and where to send their articles. People use queries on Google like this "guest post guidelines" + keyword to find guest post oppertunities. Use quotes in google query and add a keyword and you can find many other blogs that offer guest blogging. Now optimize your page so people can find you the same way.
"guest post guideliness"
That’s probably the 3 most popular search terms people use when looking for Guest Post opportunities so you will most likely get many visitors from google if you somehow put them on your page.
You can also try to look for more queries people use and put them on your guideline page somehow but be careful not to overspam your own page that way.