I'd like to record a simple song with just guitar and vocals. The song is only a few minutes long and can be done in one take. I can record both at the same time but what would you do to make it shine? How many tracks and what fx? Thanks.

 

You asked for it. This is the Coffee House where almost "anything goes".
 

Seriously,
 
If it's acoustic guitar the best way to make it shine is 
 
a) get the cleanest recorded sound you can with a 2 mic setup (google it)
b) add some very nice but very light room/reverb sound 
 
Vocals? Heck we're all trying to make them shine and have spent years chasing the elusive FX chain. And if you're like me you may never find a one size fits all approach.
 
But, get the cleanest possible recording you can and you're probably 80% there.
 
 

If it were me I'd record the (acoustic) guitar first (on two tracks). Then record the vocal on another track.
 
 

My goal:

 

Using a pop-blocker, then a de-esser and a little compression has worked for me.  Of course, if this is supposed to be a Top-40 hit, you'll need to sing off-key then overuse pitch correction. 

In essence I just want to know how to do something not to be too ashamed of to put out here. I want to do a competition for the best performance of a song of mine. And give a cash prize for it... but it's barebones. No intro no solo no backing so I can leave that to the inventive guys out here? But I'm no singer. Clarity may have been the best bet? It just seems to have no feel! I don't suppose it would matter.

I hear stuff 1 guitar 1 vox on tv that just sucks in such a way that it works and someone got paid.
 
crap.

I'd recommend setting up a click track and recording the guitar solo. This will keep you from tempo issues. Every guitar records differently and every area of a room reacts differently. Depending on the guitar, I experiment with moving the mics around the room trying to find a sweet spot. Then I experiment moving the mics around the guitar. One recommended method is putting a small condenser mic at around the 12th fret and about 10 to 12 inches from the neck, and a large condenser over your shoulder and above the sound hole. Experiment with it, and see where it sounds the best.
 
If you record it right, the mixing and treatment will be the easy part.