I double up on all guitar parts (play twice) and hard pan L & R. If it needs extra thickening then record and additional 2 guitars (again sparate takes) and pan L & R say 9 o'clock and 3 o'clock.
As the lead solo is usualy played when the vocal stopped, I tend to place the lead guitar bang in the centre, where the vocal would have been. But if the lead guitar is also doubled up then I pan each slightly L & R respectively, but not hard panned as that would clash with the rhythm guitar's space.
If there are other instreuments competing then it gets trickier, like keyboars, then you may have to use EQ to make each instrument stand out from the pack not just stereo panning.
Reverb and effects again are down to your personal taste and the sound you want to achieve. I put some slight reverb on the guitar parts. Someone once said (I think on this board) that reverb is the 'glue' that holds your mix together. i like that. Most of the tracks on my mixes have some reverb on them (all have some 'glue' to bind them to the other instruments) though it might not be a noticable amount to the listener, but it is there.
Try experimenting, what works in one song arrangement may not work well for the next one. There is no substitute for spending time experiementing and learning and developing your own sound as a result.
Oh, once you have a good sound, mic up guitar cabs properly in the first place and you're 90% there!
These are only my views i'm nowhere near an expert as you'll tell from my explanation!
