The official name of shingles is 'herpes zoster'. It is caused by the same virus as chicken pox and the two are connected - for example, you may catch chicken pox from being in contact with someone who has shingles.
Shingles begins with a tingling feeling and then is shown by a rash, usually on either the right or left side of the body around the waist area, but not crossing over to the other side. The rash is quite painful, and after a few days you may develop blisters on the same place. These can be itchy too. It is usual to feel quite sick and tired for a few days before the rash becomes visible, but a doctor may not know you have shingles until the rash appears.
Other symptoms can include pain in your arms and legs and an ache in your face muscles. Your eyes may feel weak and you have a general feeling of tiredness.
You can see what the rash looks like here.