First build advice

[Bluestribute]

I know this is my first post, but I'm really into DIY stuff (hell, I'm building myself another guitar because I want a 19EDO neck and figure if I'm going to buy one, might as well make one) and want to try my hand at amp building. Well, I figure I'll do my first project as just a cabinet instead ^_^. Anyways, any suggestions for a first complete DIY build? I want it to be open back so the dimensions shouldn't be that much of an issue (as long as it holds the speakers, the air flow and whatnot should be fine). The only other amp I've had is a 40W Line6 Spider Combo. Not a bad amp, but I think I can do better. Anyways, if I understand correctly, all I would need to do is:

Build the enclosure
Build something to hold the actual speaker
Wire the speaker to the output

Before I go on this venture, I want to make sure it's really that simple (of course, I use that term loosely because I'm sure once I start it won't be so simple). Say I use this speaker:
(*NEW*) 12" G12C/S - 75 watts | Warehouse Guitar Speakers
Would the only other material required be the wood (I like the natural look, but even if I don't, one reason I'm so into DIY is for visual customization so I'll paint it), wires, and speaker screen (besides the handles and stuff)? And of course a head but that comes after I build this . . .

Also, since I've only used combo amps, do I use a mono jack or stereo jack for the jack connector to the head? I think mono but just wanna make sure.

Anything else I'm missing? I waited a full year before building my first guitar, making sure I knew every little detail I'd need, and still wound up forgetting stuff Just don't want to dive into this, spend a few hundred bucks, and realize I need to spend a few hundred more for it to work.

[Bluestribute]

Well . . . I guess here is how I'm starting:



And 'cause that wood is old and looks crappy, I'll probably put tolex or something on it.

[booj]

I'd either mount a jack to the back of the cab somewhere and wire the speaker to it, or wire a 1/4" plug to the speaker with wires long enough to reach the output of whatever amp you want to use in either the horizontal or vertical position. 16 ga. wire.