I intend here to only talk about my own altar.  This is how I do it, it doesn't mean to say you are wrong, there are lots of right ways!

A note for those who choose to be more private about their beliefs. I choose to be open about my pagan beliefs just as others are about theirs and I personally see no reason not to be.

Athame
An athame is a ceremonial knife - Air (east)

Wand
Anyone not know what a wand is? - Fire (south)

Pentacle
Going to cover this in a section of it's own

Chalice
For water and whatever you choose, me it's usually wine - Water (west)

Censer
A container for burning incense. I actually use a mini cauldron. My favourite incense is cedar and it really helps me to connect - Air (east)

Candles
A green candle on the left of my altar represents my goddess, and a red candle on the right is for my god.

Post Card
The Chalice Wells in Glastonbury is my favourite spiritual place - Earth (north)

Candelabra
For me, the three candles represent the three aspects of the Goddess - Maiden, Mother and Wise Woman.