My Ontario family was involved in the building of the CPR across Canada. What are some ways that I can learn about their experience?

See: CPR Archives

Would there be like city directories to the Toronto areas. I cannot find any info without the proper dates but I know my great grandmother lived and died there up to mid 1940's.

Yes, there are city directories for most of Ontario's cities. This topic is covered on our City Directories page.

I would like a copy of my ggfathers naturalization record. I have all the information plus the naturalization number. So in a sense, it really isn't a search. Would I still have to pay the $75.00 they require to do a search?

According to the CIC Fee Schedule the fee for a search and the fee for a certificate without search are the same.

2010 Update:
For $5 you can apply for and receive Naturalizations Records between the years 1915-1932 using the LAC online index. You will have to provide proof of death when applying.

A census lists my ancestor as being born in "Canada ENG" - where is that?

That's difficult to answer as it has many meanings. The assumed answer would be Ontario, but that may not be entirely correct. It's safer to guess that it means your ancestor was born in Canada and their mother tongue was English. It doesn't narrow down the location but it also doesn't have you looking at just Ontario when you should also be looking at other English speaking areas of Canada (like the Maritimes). On the flip side if your ancestor was born "Canada French" assume it means they were born in Canada and their mother tongue was French (this again would not restrict your search to Quebec but to all French speaking areas)

my father was born on Jan. 5th 1948 in Fort Williams ONTario. He was adopted shortly after birth. HE recently has passed and we just found out that he was adopted. His adopted parents are also passed. I would like to find out the name of his birth mother. How would i go about this???

Contact the Adoption Disclosure Register, they'll be able to help you.

Adoption Disclosure Register
Ministry of Community and Social Services/Ministry of Children's Services
2 Bloor Street West, 24th Floor
Toronto, Ontario M7A 1E9
Tel: (416) 327-4730
Fax: (416) 327-0573

[From Cathy] You could also check out adoption reunion registries. There maybe an aunt or uncle looking for you - even cousins. Here is the best one for Canadians. It is free.