Terry Moore replies: I would not consider mahogany an oily wood. Teak and rosewood, yes, but not mahogany. For interior work such as furniture and cabinetry, regular yellow wood glue such as Titebond works well. For exterior work such as boat building or say an entrance door, epoxies or urethane (gorilla) glue would work better. In either case, no special preparation is needed beyond sanding and dusting.
Jon Siegel replies: Mahogany is not an oily wood and requires no special glue or methods.
Marty Milkovits replies: Mahogany is probably the least oily of the oily woods, It glues well with any glue intended for wood and other than making sure the surface is dry, bare wood does not require any sort of cleaning. Of more concern is selecting the right glue for the job. For general indoor projects I use an Aliphatic Resin glue (Yellow glue); outdoor or marine I’ll use a Resorcinol Resin or Urea Resin glue. If you are a purest period furniture maker, use Hide glue. The book Gluing & Clamping by Patrick Spielman is probably the best laymen’s guide for the different types of glue application.