http://www.cic.gc.ca/english/visit/apply-how.asp

Here is the link for applying to Canada. Follow the instructions and answer few question then it generates a number for you that you can use to create an account on the website. You can apply for a temporary visitor single entry or multiple visa either online or through the paper application. In the first case the website guides you through all the steps including what forms to fill up and scan. Also it is good to keep a Canadian friend's address or a hotel address handy to fill up the form. These are the documents you will need for canadian visa application, Proposed itenerary: I just wrote down an email saying my plans if the visa is granted, Proof of legal existence in US: H1b letter employer letter u20s etc, Proof of fund availability: Bank Statements, If you friend in Canada writes an invitation for you it will be great.

Paper application needs to be sent to Canadian consulate at LA or NY. In case of an online application, they will email you once approved then you will have to send your passport to LA or NY to get it stamped. You can expect your visa to be approved within 2 months at this time of the year