Seems SOMEONE has to give a quick look at the Minecraft-Wiki...
"Minecraft Man", "Nether Minerals"? They got official names, in case of latter, you even get a damn info when you hover your mouse over it.
Otherwise, that's more or less what I do in my normal runs, anyway.
1 - Get a map to be 100% explored
Got like three of those maps right now plus one for the Nether, all more or less discovered. That whole also soon gets various difficulties with the explore-part as 1.4 going to offer the ability to enlarge the area a map covers.
2 - Use the Nether to explore further areas
Well, not just that, but I build a damn railroad system in there, with trainstations and everything! Currently, it is quite linear, but I probably make it more ring-shaped or something like that further down the road.
(You should try it yourself - requires quite a lot of iron and gold to even build and then also having to make sure that no Ghast blows up your track... not THAT easy.)
I also set (and reached) myself the goal of:
* Building a tower out of Stone Brick with a size of 8x8 on the outside and a platform on the top. Size? Maxed out, 256 meters. Includes stairs and a wooded construction in the construction in the middle in a 4x4-ring-shape with a 2x2-waterfall all the way from top to bottom of the tower.
* Expand the tower to a full, small castle with a walkable, 4 blocks thick wall (walkable in the INSIDE and ON TOP)
* Have the castle feature a distractable bridge which only a player can open - from either side with switches.
* Find a village, expand it, wall it off
And currently, I decided I want to build an outpost in the village, hidden in their well (where my exit of the Nether-Railroads are hidden, btw). Also prepared myself for the upcoming update to 1.4 by having a cage for the Wither in the cellar of my base.