Warmtone papers seem to be the best for toning. I will give you a couple of examples to try and see if that is what you like.
Ilford warmtone in Zonal Pro warmtone developer and then processed normally and then selenuim toned 1:9 for about 4-5 minutes will produce a nice warm brown print.
Ilford warmtone in LPD 1:6 and afterwards selenium toned 1:9 for about 4-5 minutes will give you a eggplant ( slightly purple/warm brown print).
Ilford warmtone in LPD 1:6 then afterwards in a sepia toner will give a yellow/brown print. Sepia is a two bath process. First the image is bleached away then in the second bath, the image is replaced with a sepia/yellow image.
In my experience selenium is easier to use than sepia because it a one bath toner and you can see the results immediately and remove the print when you like.
With warmtone paper you will always get a color shift when toning in selenium. With Ilford FB (normal) you can tone for archival and will not get a very noticeable color shift. Warmtone will alway shift the color.
Most toners smell pretty strong so use gloves and have proper ventilation.
Take notes on all your processes and then you are able to duplicate it when you wish to get similar results.
With Kodak Selenium mix it 1:20 and 1:9 and keep it in plastic bottles and you can reuse it indefinately. As the color shift slows down you will know when it is time to replentish it.
Both selenium and sepia are archival.
As others have said use Tim Rudmans book, it has lots of great information.
Hope this helps,