You can find a list of guest post ideas here. Choose the blog post you do from this list.
Reminder, there is no guarantee we will use your content. We reject content for a number of reasons. The most likely one is that it was not written by native English writers or experts in the area the blog post is about.
Please put the time into researching the information contained in the post.
Most guest posts are crap. Don't write about things that have been discussed to death. If the post isn't unique and truly helpful then please don't waste your time. To use Seth Godin's term, make it a "purple cow", a post someone stops and pays attention to because it's different than the other cows.
We check guest posts for inbound links 30-45 days after they are published. If a post hasn't earned any links we tend to take it down. So make sure your post is good enough to earn at least one decent link.