Learn the ledger outline. Leger lines are lines that are further above or below the staff; there can be a lot of them, but it is most likely necessary to learn only a few from memory and know how to form out the other ones when you come across them.
Become confident with rhythm by learning the import of time signatures. A time signature is a fraction shown at the beginning of a portion of music. The top digit tells you how many beats there are in a measure, while the bottom number tells what kind of note gets one beat or count. Hence, 4/4 time would be four beats to assess with a quarter-note getting one count. Sometimes 4/4 is shown with a C, which stands for frequent time. 2/2 time is two beats to a measure with a half-note getting one count.
This is commonly called "cut time" and is typically expressed as a C with a vertical line through the center of it. Other common time signatures are 3/4, or three beats to quantify and a quarter-note getting one count, and 6/8 time. 6/8 is a little strange because if it is played in a fast tempo, there are two beats to a measure with a dotted quarter-note getting one count.