I mostly deal with hard rock/metal guitars. The pros in that genre are loud, in your face and heavy tones. The cons, at least in my experience, if you record too loud, you won't get a good final product.
A player I frequently record has a Les Paul (Gibson) and a Marshall Jmd100 and Ma412 Half Stack. In the beginning we both thought "loud is better!" then record as loud as possible. The problem I quickly learned is I record too loud, anything I add while mixing will clip the track and distort it.
I record with 2-3 mics depending on what kind of song he wants to do. For a 70's sound, I use one SM57 on the lower right section of the amp, pointing directly at the tube, 2 inches away from the speaker and maybe an inch off center. For the harder metal stuff, 2 SM57s resting on the speaker: One bottom right, one top left. Angled at maybe 25 degrees, pointing towards the center of the tube, but an inch or 2 off center. I'll use another mic as a room mic, pointed at the center of the cabinet, 3 feet away.
When recording, I tell the player to tune his amp the way he likes it played, then fine tune it listening through headphones/monitors to get the sound we want. Then he turns his amp down to maybe 75% volume, then I record at -6DB to give the wave some breathing room when I add effects and plugins. I usually ask the player to record 2 separate rythem tracks before he adds a solo/lead part. One rythem take is panned left, the other panned right. Solo/leads 40% panned left/right
With Logic 9 I can customize the amp sound to almost anything I want. While that's cool, I like the natural, real sound of the amp. All I do when I record guitars is run it through a multiband compressor, tweak the EQ's and add a touch of reverb to keep the natural sound of the amp, but make it big and badass sounding.
Here are songs I did with the techniques I just described. They were recorded in a basement using nothing but heavy blankets and carpets to dampen the room noise and basic microphones (SM57, SM58 for guitar/bass/vocal. EV PL33, PL35 for drums). Nine Ways (Metal) (Guitar, Drums Only) by Brainstu Hammy on SoundCloud - Create, record and share your sounds for free Piece Of It (Generic Rock) by Brainstu Hammy on SoundCloud - Create, record and share your sounds for free Lies (Hard Rock) by Brainstu Hammy on SoundCloud - Create, record and share your sounds for free