As lostamonkey mentioned, there is no such thing as a "Vanguard Account" in Canada (yet).
However, Canadians can buy either US-listed or Canadian-listed Vanguard funds via our domestic brokerages. If you're interested in that path,
this article is indispensable.
Investing in the Canadian-listed funds is pretty straightforward.
If you have read the article above and decided that your RRSP deserves US-listed funds, do your research properly - the fee structures for US dollar accounts/transactions are all over the map, and it's annoying to discover that what you saved in management fees you then lost to wire transfer charges or currency conversions.
I found Questrade to be a good option for trading in USD. Free inbound transfers using the auto-deposit feature, no maintenance fees, and no commission when buying ETFs.
For some reason, they don't seem to carry Vanguard mutual funds however - only ETFs. So you can't buy e.g. VTSAX, but you can buy VTI, which is functionally equivalent.