Before you get too far along, look at this example:



This is the same music, but with two new symbols, the downstroke and the upstroke.



These symbols tell you which direction to move the pick - down or up.

The easy way to tell the difference is to think of containers. The downstroke sign will spill downwards, the upstroke, upwards.

Notice how most of the time down and up alternates. Sometimes this doesn't happen, like at the beginning of the third measure. Here two downstrokes had to follow each other because it is also important to play a downstroke on the first beat of a measure (which is sometimes called the downbeat).