Suspension designs like found on the bajaboard have leaning wheels but that would make this thread messy so non suspension designs mostly is the focus.
there is a lot of good into dropped by @Flexboardz in this old forum thread
but they are also here so ask them questions and quote stuff in their thread here
As far as I know, there are 2 designs for leaning wheels : longitudinal design with longitudinal swing arms (like BMW streetcarver of Flexboardz) and transversal design with transversal parallélogram (like Leanskateboards) or double wishbone (like Baja and few others).
Suspension is another subject (fantasm?) (and Flexboardz has suspensions too)