Where do we go from here?
First go to the Canadian Government site and get the forms.
CIC Site link
What happens next will vary a little depending on where you are applying and what comes through with the application kit. Whatever you do follow the instructions in your kit. If it conflicts with what you read here, don't worry. Do what they are telling you to do. Also, and I cannot stress this enough, tell the truth! If you make a mistake on the form and realise later, let them know. Remember to quote your file number. They will not penalise you for honest mistakes. They are not looking for ways to trip you up. Remember Canada needs immigrants. They want you to be successful and happy. They need to assess if you will be able to make it here. They can only do that if they have all the facts. There is no point in claiming to be a rocket scientist just to get extra points if you find yourself unemployable after you get here because you don't know which end of a rocket points up. :o) If you do lie and they catch you then you may not even be able to visit Canada for two years let alone apply again.
While waiting for the forms to arrive....
If you have requested forms by mail it will speed things up if you get some things together. You will need birth certificates for everyone who will be included in the application. If married you will need a copy of your marriage certificate. If divorced you will need those papers too. You need copies of educational qualifications and certificates. If these documents are not in English or French then you need to get certified translations. Try to get references from past and present employers. If you don't want your present employer to know that you might be leaving and disappearing off to another country then just leave it. The Canadian Immigration authorities understand this. Provide proof of employment by getting copies of pay slips and a job description if possible.
You need to get together evidence of your finances. There are minimum amounts depending on the number of people included in your application. At the point of application evidence of finances can be in the form of cash or in the form of possessions - house, car, investments. However it must be your money and not loaned to you. If you have a job arranged you do not need to show proof of funds BUT arranging any kind of employment before getting a visa and landing is extremely difficult so don;t bank on that. I will talk about money later but just as a word of warning, don't underestimate this. You are going to need quite a bit when you first arrive.
These pages should help you with the process.