How you record your vocals, and how many tracks you use, is all up to you. I've done alot of different things in the last couple of years that I've been recording, but as of late I'm using pretty much one way over all the rest. I start with one main track, which I use as the foundation. This track has to be perfect, 100% from start to finish or damn close to it. From there I have them do about 3-4 adlib tracks.
I've found that rareley do cats ever have a perfect adlib so what I do is go thru all the adlib tracks and pick and chose the best parts ( it's called comping vocals ) cause maybe this word on track 3 sounds better than the one on track 2 etc... once I pick out the best adlib's, I move them all to one track so now there is only 2 vocal tracks, the main vocal and the addlib track. I do this because I prefer a cleaner vocal track, compared to the heavy layered sound of say 2 pac ( which I do like and some cats I do have them do multipule vocal tracks ).
I leave the main track paned dead center, and pan the addlib slightley to the right. As to effects. I useally use waves Ren comp, sometimes a bombfactory LA-2A and useally between 3-6 db of compression, just depends on those specfic vocal tracks. I only EQ if the track relly needs it and useally pretty light. Then set us two mix buss'es. One for Reverb ( waves ren verb), useally a plate, I do have a nice room one I've made though, just depends on the vocals, and the second send is used for delay, which is a very light slap delay set around 30ms, and only brought up very little to enhance the vocals lightley ( IE to add fullness ).
I prefer a more cleaner but fuller sounding vocals, that are not heavyley layerd, just the way I like them to sound. Its not right or wrong, just one way.