ETFs - generally go for the one with the lowest MER that isn't of some oddball tax structure (unless it benefits you... which is beyond my understanding, should probably see tax specialist, etc). In short - avoid 'tax friendly swap structure', 'hedged' and so on unless you know why!!
Canadian: ZCN
CAD Real Estate ZRE (or VRE, which is cheaper, but less diversified)
US: VTI I think is the right one, but ideally in your RRSP. Also note that converting CAD$ to US$ is not cheap (2.5%) unless you can figure out a clever way of doing it (Norbert's Gambit, or open an RBC US$ savings account, and use a forex company to send from CAD$ to US$ at a much better rate, say 1.5%). Ugh. Ok, so basically just figure you'll lose $25 per $1k. If you do go with Questrade MAKE SURE YOU SET YOUR ACCOUNTS TO SETTLE IN ORIGINATING CURRENCY (else they will convert any US$ dividends back to CAD$) - you want to do this when YOU want to do it.
International - Well, up til now its all been VXUS but as from today's Canadian Couch Potato, there are a couple of iShares funds. The big problem with these is that they are foreign investments in a US$ ETF in a CAD$ ETF. It doesn't matter if you are in an RRSP or TFSA, you WILL lose the US withholding tax, AND any foreign withholding tax. Personally I would just convert to US$ and buy the 'native' funds - there is NO withholding tax on the US end of stuff in an RRSP WHEN IT IS A US$ fund.
However for *simplicity* just hold these new CAD$ accounts. You will not lose the 2.5% currency conversion fee at all, but your dividends will take a hit.
To be honest it is a right bugger being Canadian - with such a relatively small and concentrated stockmarket. I have stuff from the UK still, in a British brokerage, and the access is much better, the ISA (== TFSA) bigger though it doesn't roll over from year to year, etc... oh well!
Um. The reason I personally go for ZCN (or XIC, if you're an iShares fan) is that it holds the TSX composite (=254 companies) not the TSX60 (=... let me look that up!). Even with the Composite, a few companies make up an unfortunate proportion of the index (RBC, TD, ScotiaBank, CIBC, and BMO are like... 20%+ of ALL Canadian market cap!!).
Ok, rambling, rambling. Hope this is useful to someone!
Basically you can't go too far wrong with CCP's advice. To start, just having XBB (bond index) at your age, VTI, VXUS and ZCN will do you right... You've got bonds (stability) and The World there. Literally - the world. You could even skip the ZCN if you wanted, as VXUS does hold a chunk of Canadian stuff...