There are typically between 4 bans and 6 bands on a resistor. You must be very careful when reading them because after a long day working some colors can start to blend.
The first 2-3 bands represent single digits, there will then be a band representing the multiplier, a space, and then a tolerance band. On some occasions there will be a temperature coefficient band at the end.
The easiest way to learn to read it is to imagine writing the numbers down on paper
for example, say we have a resistor with the following colored bands : BROWN, GREEN, RED, GOLD
This would represent the following:
BROWN - GREEN - RED - GOLD
1 5 X100 +/-5%
so it is simply 15 x 100 +/- 5%
so you would be holding a 1500 ohm resistor with a 5% tolerance (meaning the resistor value can actually be anywhere between 1425 and 1575)
And thats it, pretty simply to pick up, i wouldnt worry about memorizing the colors, You get used to them after a while but i always have a card nearby with the color codes on them too.
Photo credit : michaels-electronics-lessons.com/