Tutorials/Shelters

There are several things every minecraft shelter should have.

This is the single most important room and should be the first one built. A kitchen should include a crafting table, at least one furnace, and at least one chest containing key crafting materials.
 * A Kitchen

A room full of chests for storing all of the dirt, cobblestone and other materials that accumulates in your inventory while mining.
 * A Storeroom

It's generally a good idea to put the entrance to you mine inside your shelter. If you return at night, you won't have to make a mad dash to your house.
 * The Entrance to Your Mine

A room with a lava pit, for disposing of unwanted materials.
 * An Incinerator

or, if you would rather not risk fire or death, put a 3x3 pit (4 deep) with water sources in each corner, a sand block in the middle of the floor and a cactus on that

Since spiders can climb walls some form of a celling overhang is a good idea to have.
 * An Overhang

Other Ideas
There are any number of things to add to your shelter and here are just a few of them (ideas needed, don't feel shy to add stuff!):

1. Add underground floors to your shelter.

Using this gives you a chance to find resources and in the case of invasion by mobs it will always provide a safer spot.

2. Add aboveground floors to your shelter.

It is advised to normally do this after building underground floors if you have a lack of resources. This could even give you a chance to "snipe" some creepers and spiders in the morning.

3. Build a mob pit.

Basically a 3 wide and 2 down pit around your houses preventing mobs getting too close for comfort, and can later be expanded into a mob killer (requires lots of ladders).

4. Build a moat.

Don't they just look so cool in lava (don't forget to destroy all nearby wood :P ) (and water :P).

5. Make a farm extension.

Look at the farming tutorial for more on this. :)

6. Remake it out of a different material.

So much potential here!

7. Make a base in a new location.

Having more than one base helps if you need to travel farther to get resources. A base next to your spawn point is helpful if you built your main base somewhere else.

8. Make a panic room.

Put tnt throughout your base and have redstone leading to your panic room.

9. Make an underground farm and tree grower.

If you have a shelter underground, it might be a good idea to have these. Returning to the surface may be tough and dangerous.

10. Make an indoor animal farm

Works well if you built a large structure (such as a castle) on grass, simply light up the ground level and passive mobs will spawn inside your home every day, so you can hunt without any risks

11. Lava lamp

Simply make a hollow space out of glass and fill it with lava, an efficient method is to run a vertical collumn through many floors powered by a single lava block at the top. A word of warning, don't carry swords around glass containing lava, you never know when you might accidently bump that left mouse button...