soulgirl,

As said by Romas, the site has everything you need. Visit the website. Read thoroughly. You can find there
No need to use middleman

1. Application guidlines
2. Application
3. Requirements for applicxation.
4. Online test etc

You just need to spent few hrs. Thats it. If the nurse is in priority list ( National Occupational Classification (NOC) you can immigrate within a year or so. If not, it may take two or more years depending upon the place where your application is processed. From Nepal it usually takes 5-6 years if the profession is not in the priority list.

From US it may take up to 2 years if your profession is not in priority list. Application processing time depends on the application processing office.
First you find out where you have to sent your application ( you can find it in above mentione site)
Then go to the website of application processing office, there you will find how long will it take to process your application.

Job situation in Canada:


It is not that difficult to find regular job ( if you know what I mean)
If you are a nusre and want  to work as a registered nurse, which is a high salary job, you need a Canadian licence. As far as I know US licence is not acceptable. Canadain licence is exam is not that easy but not that difficult either. You  can work in private clinics, but usually, they dont pay much.
Old peoples care center is another option where you dont need licence.

Tax

Tax is high.

Things which are free in canada ( offcourse tax payers pay for it)

School education and health care is free. Depending upon the income level, medicine is also free with some deductable. Emergency care is free too except for the ambulance.

Compared to US life is bit slow in Canada.Crime is less too.

have fun