try these first-

Canstock
123RF
Depositphotos
Fotolia
Dreamstime
Alamy
Envato
Veer

Test the waters -if you get in that try Shutter and iStock

Do not be come exclusive to any single company....

I am relatively new and I am cutting my teeth on the following

Canstock
123RF
Dreamstime
iStock

I just started putting some of my more artsy work up on Fine Art America as well

I am also testing the waters trying to sell direct using Symbiostock.

I would say good luck but more apprpriately "work hard"   

-Tim

Normally, you can submit the same photos over multiple agencies unless you choose an exclusive deal (image-exclusive or artist-exclusive) and with the caveat that you should not submit images you have RF elsewhere as RM at Alamy.

Other than that, be very careful which agencies you choose.
Some sell cheap, so you make cents per sale.
Some offer very small percentages.
Some are not transparent over what percentage you get.
Some spread your photos over many partners and it can be difficult to keep track.
Some have a long 'takedown' period during which your photos are locked in.
Some muck you around, lie to you, and change the goalposts every other week.

Only you can decide your personal tolerance for all that cr*p.
Read the contracts very, very carefully, reading  between the lines.
Plus there are some which seem to treat the contributor with more respect, but don't sell much.
If your style fits  , why not try Stocksy?

FWIW, 'portraits' aren't likely to be worth pursuing for stock.

Make sure you take the time to see what is already being offered for sale on the top sites. If you can't upload "better" images or images with "better" keywords don't try it unless you just want to test the waters or boost your ego when/if your images are accepted. Landscapes are a dime (literally) a dozen and unless you can upload photos that are better than the thousands already on the sites you will be disappointed. I read a post on a microstock forum last week where a contributor was complaining that he/she has had a whole 50 images online for 3 months and why wasn't he/she getting sales. Not a get rich scheme these days.

Thank you so much, Joy and Curvabezier. I mentioned CanStockPhotos only because that came up when I was looking for Stock reviews and this forum came up.

Yes, I have been looking at Shutterstock and would like to give them a try. I went on their site to look at the galleries. I like what they have. I appreciate your feed back. It is very helpful..

Thank you again,

Erich

I would recommend a slightly slower approach.  Start with Can stock to learn how to shoot, keyword, process and upload.  Work on getting your workflow steps down to an efficient process.

When you are able to get 100% acceptance at Canstock, not hard really, then take your skills to 123rf, dreams time and Shutter stock.  IMHO, you are just looking at frustration at SS unless you can get 100% at CS.  SS is much harder and will not take many that CS does but you will have better skills and a small portfolio to work with.

without in shutterstock, one won't really make money to continue this 'hobbies'..


and stock photos aren't about beautiful photos, it is more about 'useful' photos..same as illustrations..

There's no point in starting off with sites which hardly sell anything, it's a surefire way to lose interest. If you can get on Shutterstock then at least you have a reasonable chance of making some sales, even if you only get 25c for them, or whatever the starting rate is.

I get fewer than 40 sales a month from Canstock with about 4,000 files there, and I'm pretty good at this game, so how many photos do you think you would need to put there to get your first 25c sale?

At some point you'll just have to do your own research and start figuring things out.  Asking for too many shortcuts from people who have invested a lot of time and effort learning the ins and out is just going to tick people off.

All the sites have FAQs and there are a couple of books on Amazon that explain everything about the industry for under $20.

A few notes to think over:

It depends on your portfolio, but starting with stockphotography in 2014 has become difficult.
You need to learn a lot and need a lot of energy, enthusiasm and patience too. But the most you need is propably a stubborn persistence!

When a photographer starts to submit his images to any stockagency he/she has mostly not a realistic view on what agencies accept when it comes to technical quality. You need to learn to look at your images in a different way you did before. What friends and family think of your images doesn't make sense. Your impressions at this stage, good or bad, with an agency doesn't make sense either.

The reactions you've got from others on this forum are based on their personal experience with each agency and depends on the kind of portfolio a contributor has. Some do very well with a particular agency, for others it is disappointing. You can only find out for yourself over time, but you need to have at least 1000 images accepted with an agency, otherwise conclusions doesn't make sense.
So it is not possible to draw conclusions out of the submitting of 30 images. When you get one reviewer with a �bad hair day� everything gets rejected for example.

Getting 7 out of 13 (4 mp images from 2007 and not especially shoot for stock) accepted at Fotolia at a first try is a good result. You were lucky or your images are very good,  but getting 27 out of 30 rejected at Dreamstime is just a very bad result. Could have been a reviewer with a headache, but I doubt.
Istock seem to accept everything these days, so no conclusions either. Too early to decide to go exclusive or not with an agency, because you don't know if your images will get sales at all.