I worked as a contractor and an employee, a couple of times for the same company. Nortel was one of them. My rates were $50 ~ $80 as a contractor, depends on the project and which department. The biggest downside was gigs can be terminated with no notice, and there can be some laps of time in-between gigs. First level contractor with IBM can net $70-$100, second level subcontractor can net $50-$60.
If only doing side projects, you can get a GST number, and bill yourself out as a company. Don't really need to register for a company, no coporate filing at year end. Some expenses can be claimed and deducted. I believe 15% of the home can be claimed as business expenses, along with the all the utility bills. Vehicle usage can be used as claim, make a mileage log. There are a lot of benefit of having a side business, added income and deductible expenses.
Lastly, get a good accountant.