I play Minecraft multiplayer only these days so I can just use commands to spawn items, however, for those of you that play single player I had Tormented Ghost write up a guide on how to use Invedit; it is a program that spawns items for you allowing you to focus on building and not on gathering. Here is his guide, if it leaves any questions unanswered you can read the instructions on the download page or ask in the comments.
"To download Invedit click here.
This is the beginning screen to Invedit, basic and understandable. All you gotta do is open your world.
And it opens a grid the size of your inventory.
Then grab something from the right bar, and drag it into one of the squares. You can put armor right into their squares.
You can adjust the count and how much damage it has ( you can go negative)
Max Count: 255
Minimum damage -32657
Then you save back to the world via the save button and open Minecraft. It may look like you only have one of an item but you actually have 255. And with all that you get:
This world is going to be the start of a sort of lets build just comment ideas of something for me to build and I will try and build it and take screen shots after a while (when I get bored) I will make some sort of competition and give the world away."
There you go, Tormented Ghost's guide to Invedit.