Depends on personal taste. Maple necks are more commonly used by lead guitarists, mahogany is more commonly used by rhythm guitarists. That's not across the board though, it's largely personal preference.

Guitars also depend on the specific wood used. You can make two identical guitars from identical species and set the up the exact same way and they'll feel and sound different. When talking about wood it's always important to remember that characteristics of a species are generalizations and differences do occur.

That's one reason when you're buying a guitar like a strat or tele it's important to try out as many as possible and find the one you like best, because specific chunks of wood can and do have a huge influence on the finished product.

As far as lead guitars having more treble that depends on the pickups. Woods like maple are brighter, but the balance between the treble and mids and bass is going to be mostly interpreted by the pickups. To continue generalizing, lead guitarists tend to use thinner strings and rhythm guitarists tend to use thicker, guitars made more for lead work can have thinner necks (such as the Ibanez JEM) and rhythm guitars tend to have thicker necks (although exceptions are very common due to personal tastes in feel and hand size), and lead guitars tend to have less complex electronics because the more wiring the sound goes through the less bright it sounds.