I'm making an RPG for my group based around the X-COM universe. For the Geoscape portion, I need a high resolution printable map of Earth. I've made some maps for RPGs before, but always by hand and never of the actual Earth (on a world scale, anyway), so I'm quite new to this cartography business.

In short, I need a program that can help me make a high resolution map that has a grid over it. Each grid square must be the same size and (here's the part I was having problems with) must contain the same surface area worth of Earth. This is for aircraft, so I'm not worried about rough travel or landmasses.

There will obviously be issues with poles and probably other things I don't even know about, but any help on this whole thing would be appreciated.

Even if it's telling me my method sucks and proposing something better.

Thanks for tolerating the new guy,
Krillsack