Here is a handy PDF you can download and print out. It shows all the notes up the neck of an electric bass.
Click this link to download the neck diagram: Notes on the electric bass
Here are a couple of interesting facts about the “bass guitar”.
1. The instrument we usually refer to as the bass guitar is really an electric version of a double bass, with a small guitar-like body and much shorter scale (length). It is derived from the double bass and not the guitar.
2. The most common electric bass has 4 strings and is tuned G D A E. There are also 5-string basses, usually with a low B string added, and 6-string basses with one low B string and an extra high C string added.
3. There are six string bass guitars that are tuned the same way as a normal guitar but one octave lower. Well-known examples of such instruments include the Fender VI, and the first such electric instrument made by Danelectro in the late 1950’s.
4. Mexican “mariachi” music uses a bass guitar, the guitarrón mexicano. It is a large acoustic instrument that looks like a huge classical guitar. It is usually tuned A D G C E A, and is fretless like a double bass.
5. The first string on a bass, like on a guitar, is the one closest to the floor. They are numbered like the floors on a building: first is closest to the ground, 4th is highest up in the air.