Depending on what the task is, I agree with oDesk and bestjobs.ph.
The most important part in finding good employees are a good interview process and your own management skills.
In the interview process on odesk/elance give them these questions. If they are really interested in the job, they will answer and it helps to weed out 75% of the wannabe VA's, not motivated, etc. BEFORE ever interviewing them (time savings).
Examples questions when looking for a general VA on oDesk/elance/etc.:
a) Who is the Quarterback for the St. Louis Rams and what is his current TD/INT ratio?
b) What programs are currently available for article spinning?
c) What are the top 5 keywords people use to search for office furniture?
d) What are your top 5 Wordpress plug ins and why?
e) If I would ask you for 3 wordpress themes that would fit a country western site which would you recommend? How about a fitness site for women? (Please send me to the locations where I can look at them)
f) In 100 words: What about this job interests you? How do you think you can contribute?
Reasons:
a) Lets you see how familiar with American culture they are. While you think this question is no big deal, someone in India or PH with no background about American Football will have NO clue what you are talking about. This will also give you insight into their research capabilities. Will they send you just the starting qb info? Info for all qb's on the roster?
b) Gives you a quick overview if they have any SEO knowledge, do they know what article spinning is? how to do it? what programs are out there. Also, as a bonus they will sometimes surprise you and throw out a program you have not heard about
c) Keyword research skills
d) Wordpress skills, plus you get an example on how they think and what they value
e) Wordpress theme skills and it will give you an insight into their design/cultural skills. You'd be surprised what they consider country western/fitness in india/ph
f) Here you'll get a good idea about their article writing skills, general language skills and why they would be interested in the job.
If they are interested in the job and are a real 'hustler' they find answers to all the questions. Their answers will give a huge amount of information about them and you can narrow your list down to the top 5/top 10. From there you start the actual interview to see if you personally mesh with them and find the best 3 VA's for the job. Hire them for a one to two week trial. Usually, from there you'll find one or two individuals you like to work with for an extended amount of time.
Always make sure you have two VA's from different areas available at the same time. Sick days, bad weather, death in the family etc. can be a real killer when you are on a tight deadline. From there, have those two help you to find more VA's for you. Just make sure they are independent from each other so that they don't have the ability to shut your business down etc..
$$ depend from country to country. A decent 'general VA' in PH should run around $250-$300 a month. Throw in some technical skills and good English knowledge and you are looking around $400.
If you are looking for someone to write GOOD articles and ebooks, copy etc. I would ALWAYS look local first. It's not worth the money savings to dick around with some of the most important part of your business. 95% of the time you can tell a non-native writer...
Second big part is how good you are in managing a VA. Are your instructions clear and understandable? Do you know the actual 'work' involved? Have you ever done the same work before yourself? Do you have rough metrics how long a task like this 'should' take? Can you pay by the project or do you do by the hour? Are you instructions clear and understandable? (Yes, it's repeated on purpose). Do you have little camtasia training videos on how EXACTLY your VA is suppose to perform your work? In the beginning, you should spot check their work more frequently and then let go slowly, once comfortable with their output.
I've learned the hard way that most of the time that I have a crappy employee, it's because "I" am a crappy manager and do not give them the proper tools to succeed (Time, education, proper instructions, etc.).
Hope this helps someone...