I feel at this point I know a good bit about Sonar.. however, I find not so much time to practice mixing other than mixing my own song every 4/5 months. 3 mixing practices a year is not good. But, it would be nice if I could have access to tracks and mix and get critic from professionals. Are there companies like that?
 
Thanks in advance.

Shahed

I joined Dueling Mixes a year ago and haven't looked back since.

You van also put your own music up on our songs forum and folks there will be happy to offer appropriate and constructive criticism.

And if you need more music to mix, http://www.cambridge-mt.com/ms-mtk.htm has lots of free songs for mixing practice. Not sure about the criticizing, though. 

Sure I'll do it!  :-)
 
Just kidding, my mixes prolly suck.

sausy1981
I joined Dueling Mixes a year ago and haven't looked back since.

Nevermind - found the cost $27/month.

Almost every music forum has a place you can post songs. I think there's even one on the Telecaster Forum. 
Everybody has an opinion so it's a matter of who's opinion you are seeking. 
Of course a professional engineer will offer theirs but will charge for their time. I would't bother unless your dead serious about becoming a professional yourself.  If you have the time, seeking opinions for free from your peer groups on forms is very worth while. 
My only complaint is some of the responses are not so helpful so you have to learn to read between the lines. Like all things free it come with a cost. 

Here is an example of what can happen here in the Songs forum.
 
http://forum.cakewalk.com/FindPost/3234254
 
Don't listen to the youtube until you've checked out the soundcloud.
 
After a few changes he uploaded at soundcloud, he overwrote the original youtube video.
So the last soundcloud and the youtube  are the end result. 

Zargg71
And if you need more music to mix, http://www.cambridge-mt.com/ms-mtk.htm has lots of free songs for mixing practice. Not sure about the criticizing, though. 

FWIW, the book that this website was developed to support (Mike Senior's "Mixing Secrets") is very good. He's recently released a new, companion book ("Recording Secrets") that I want to check out.

Our beloved forum guru Danny Danzi provides proffessional mix analysis for a reasonable fee. He sent me a sample analysis once and it is very throrough (graphs and point by point suggestions... very nicely done). The dude cuts some of the cleanest mixes I've ever heard. I've just been waiting until I have something worthwhile to send him (and I've got a few bucks kicking around) before getting one from him.