If you know for sure you will need a really good antenna, I would suggest this other tutorial.
You don't need more than:
a balun impedance adaptor (close look below);
1m long rigid copper wire;
a stantard shoebox (if there is a standard);
some aluminum foil
a plier and some utility knives.
Oh, after the antenna is ready, you will connect it to the tuner through a RG-6 coaxial cable with F connectors, so you just might buy some of that at the hardware store too.
Step 1: Active elements
You pluck 4 holes on the sides of the shoebox (the shortest sides, near the bottom). They should make a rectangle that is nearly 12cm X 30cm. Then you use them to shape a bow-tie with the wire and keep the ends near the centre.
Then you expose the conductor, cutting off a small section of the plastic coating (which you may keep to cover them once the balun is inserted).
Inserting the balun may be tricky, but it was pretty easy once I figured out I could use the plier to fold the conector's tips, use a small spike to widen the plastic coating and stick the balun's conectors right in it. You can always solder them later if you you're up for it.