These are my primary weapon, red ticonderoga pencils. I used to use the carmine red Prismacolours but these are just softer and slide easier along the page. You can find them in almost any office supply store and even Wal-Mart in Canada carries them. I've actually had more trouble locating them in art stores than not.
Usually you can find them in a pack of 12 and they'll last you a good while. My roomate at the time had brought me home a pack once from the Sheridan Bookstore and I haven't looked back since.
Since I'm at it I'll also show you the sketchbook I exclusively draw in.
These guys, for me, are the holy grail of sketchbooks. I have a stock pile of them.
I wasn't joking :) I've been using them since 2007 and despite trying a plethora of other sketchbooks, I keep coming back to these. All mine are the 8x10 format. I suggest you give them a try, especially if you live in the states because as far as I can tell your best bet for getting them is ordering them online at Dick Blick
Cheers everyone! Thanks for the excellent comments so far!