Overall prizes consist only of XFL memorabilia. Leagues consist of head to head or rotisserie scoring, depending on the preference of the owners of each respective league. However, all players start the XFL season with the same salary. One major rule change that changes fantasy strategy in the XFL calls for no kicked extra points. Teams will line up from the 2-yard line and either run or pass for a conversion.
Kickers only kick field goals, thereby lowering the value of kickers.
Many contests for the XFL did not materialize. Apparently, the XFL made an agreement with only a few companies for exclusive rights to provide national fantasy contests. This site also has links to the individual team websites. A good way to get some information is just to check out the coaching staffs and rosters of the XFL teams. Fantasy Football Index has a free preseason preview with preseason rankings and analysis that beat anything I've seen offered elsewhere.