The more specific your instructions the better the results will be. Even though they speak english be prepared for some mis-communication at first. Use small words and short sentences when you can, especially at the start. I have found that lists and bullet points work much better than paragraphs.
Do not be afraid to cut them loose if they do not work out. Sometimes it takes a few tries to find the right people. You can usually tell within a week or two at most if they will work out. You do have to manage your expectations, if you think you are going to be able to just off load all your seo work the first week and not have to worry about it any more you are just setting yourself and them up for failure.
Start them out with very specific tasks ie: build these links on these sites using this anchor text. Have them send you a report daily so you can check and make corrections. I have found that an excel spreadsheet works great for this. Make corrections send anything back that needs to be redone. Once they have a task down then you can just spot check. Every time you assign a new task you need to follow the same proceedure. Honestly it can be as much work at first but long term it can be worth it.
