谢谢大家的鼓励。 私地下收到好多关于运作的问题， 为了节省时间， 我就在这里一并作答了。

#1, Apply to one of the stock agency on my blog, each site has it's own rules and regulations, so do one at time.

#2 Prepare to upload your first batch of photos, find 10 of your best photos, and view them at 100% crop, no visible artifacts allowed, accurate exposure, and white balance, noise is not allowed either, if you have some pictures are otherwise perfect, then use www.neatimage.com to download a trial version, you can eliminate some of the noise, make sure you don't over done it. If you are serious into this, you need to buy a Photoshop plug in full version to speed up your work flow.

#3 After identified 10 best photos ( no logo, no visible people's face, no signs ), then you need use your image editor software like Nikon Viewer, Photoshop to input IPTC keywords, use 20-50 keywords to identify your image, ( keywords have to be related to your image ) otherwise your picture will be buried among millions of images, nobody will see it.
In Nikon browser, go to file, IPTC Information, then enter your keywords

#4 Once you are ready with your image, now you need to have a FTP client to help you upload files to various sites, of course initially you can manually submit through the website http mode, but once you get going, you need to have a FTP to speed up things, I often process a batch of 20-50, and upload all at once through FTP to 5 sites at once, I leave it alone for an hour, and come back to finish the catergory and file name after uploading.
Initially it will take a lot of time for you just to submit a few, but after a month or so, you will speed up fairly quickly.
If you don't have FTP client already, here is one very good one: http://www.smartftp.com/

#5 Some site has more restriction than others, like shutterstock, you need to have 10 submitted, and have 7 of 10 approved to get in, if you did not get your batch of 10 approved at least 70%, they will deny your application, and you can not submit to them for at least 30 days.

#6 Getty Image's Istock is the toughest, it only requires 3 for the application, and they have the highest standard in approving photos, any minor defects will be picked up, like one dead pixel out of 10mp picture will be rejected, it has to be cloned out.

#7 Some agencies are easy to join, like Bigstock and FT, and approval is very easy.
( but of course your photo still has to be technically sound, we are talking about commerical photos, not art )

#8 Flowers are not welcome, unless it is really unique, otherwise don't bother to send in lots of flower shots.

#9 After that, you can sit back and start enjoy.

Here is blog link: http://stockagency.blogspot.com/

Warning: It is very addictive, most of us posting online just try to get recognized, not to make a dime out of it, now all of sudden, not only people recognize your picture, they place their confidence vote with their money,  and publish your photos around the world, so refrain from over doing it, I have personal experience to support that, please slow down, and enjoy the process.
 After all it  is still a hobby that you enjoy.