As a self employed person you submit your own taxes at tax time unlike an employed person where the employer takes 'a portion' off of each pay cheque for you so you do not have a big ole bill at tax time ... self employed people are required to pay both income tax and Canada Pension Plan ~ we have until June 15th to submit our taxes without penalty however if you OWE you would have to pay interest from April 30th so IME it is easier to just get them done at the same time as everyone else specially since your spouse if 'employed' will need to know your income by April 30th anyway cause it will affect his taxes.

How much you pay will depend on a few things that determine your 'tax bracket' ... your own gross revenue minus your business expenses that determines your actual 'taxable income', your total household income and how many dependents your household has which will determine any provincial grants you might be eligible for and so forth which will lower the total income tax payable for you.

IME 20% of your weekly income is a good amount of money to set aside for 'taxes / rainy day savings' this way if you do not need it ALL at tax time it can remain in your business savings account for the next business year if you have a slow enrollment time, a large repair bill or an illness where you need access to some savings.

As for receipts yes ALL clients who pay for your businesses services require a receipt for the childcare even if they pay you extended hour fees, late to pick up fees and so forth that is all 'income' for you and a 'childcare expense' for them ... the only thing I would not provide childcare tax receipts for are outstanding account charges you may charge to a client ~ aka should they bounce a cheque and you charge them $25 or if they pay their weekly fees late and you charge a late payment fee because those are not 'child care costs' they are penalties for having outstanding accounts and they should not be getting a tax break for that ... you have to claim that income on your taxes as other business income but they do not get a 'receipt' for it

Hope that helps