one thing to keep in mind: a constant toner will produce different results on each type of paper. that said, i can speak to agfa, sterling (nla), luminos, oriental, and some other off brands. take the number of papers times the number of toners and i could write a volume. i will focus on agfa since that is my normal paper of choice.
agfa mcc rc in
selenium: for a nicely graded tone print, i typically use a 1:12 dilution at about 20c. times are somewhat irrelevant for asthetics as this is a room light wysiwyg process. for archival purposes, i tone to completion (about 7 minutes), but i rarely do it for total archival reasons. if i have a higher contrast print (grade 3+), i will usually use a 1:10 dilution at around 25c. this will hit the blacks hard and quickly. i can usually get away with a selenium tone on agfa with no apparent color shift, but sometimes it will move to a light lilac (kinda nice).
i really, really love to do sepia/blue split tones. the instructions for each are included in the packages. keep in mind that the sepia will grab the highlights first and the blue will hit all the values at the same time. for this reason, sepia tone first, then blue. 20c is just fine, though it makes no real difference.
your 'color wheel' toners (blue, green, etc) will go after the entire print at once (from blacks to whites) while other toners start at either the blacks or whites and you can pull when the desired effect has been achieved. the only color toner i use is blue as it is quite versatile in splits. selenium/blue splits are also quite nice.
if it were me, i'd stay away from the color toners, especially as a maiden venture. they work well in combination with selenium and sepia.
my recommendation? selenium, sepia, and blue. you can get some excellent results individually and in combinations (splits).
this is one on which i did a selenium/sepia split:
http://www.thephotoforum.com/forum/viewtopic.php?t=1424
any other questions, just post away.