Wow, talk about using really dated methods (for the fermenting part at least) and not having key information... Where did you get the kit? I would call them up to find out what yeast they sold you, and what it's temperature range is.
Personally, I've yet to use dry yeast for any beer. I've been using the Wyeast Activator packs, researching (ahead of time, online) what the yeast characteristics, and temperature range is, before selecting it.
Conventional wisdom is to allow brews to remain in primary for 2-4 weeks before bottling/kegging, longer for higher gravity (OG) brews. For something with a target OG of 1.042-1.046, 3-4 weeks is good/safe...
Without knowing what yeast they sold you, however, there's no way to know if you're still within it's happy range. You could be at the low end of the range (nothing wrong with that)... Or it could just be a strain that shows more activity for the first week, or so, then slows down (visibly, but is still working away)... You should make sure the airlock is filled to the proper level (or range) and wait for activity. Typically, even when it's slow, you'll still see some movement. It might take 5+ minutes between airlock burps, but it will be there.
Still, I wouldn't worry about not SEEING activity. Let it run for the already mentioned weeks, and then take another hydrometer reading and taste it. If you to that after 2 weeks, then 3 weeks, then 4 weeks, you should see a progression where it's getting better with time.
I can't get over how little real info is on that recipe you linked to... Not even telling what hops were included.