Some incidental nudity, but expressed in a medical/sociological/scientific context, not in a sexualized way.
\Because pretty much anybody can edit the content of the site, some information can be wrong or offensive, but the number of people who want it to accurate way outnumber the vandals, and generally repair things pretty quickly.
Wikipedia is a great place to find information on almost any topic. It has a policy that does not allow people's personal opinions on subjects to be presented, which makes it quite accurate for being a public archive. Politics and religion are discussed on some pages, but again, it is not people's opinions, merely the facts. Not all information is 100% reliable, so you might need to verify several details elsewhere.