Ok lets say I'm thinking about using the name somethingxzxzxz.com there is already a trademark for xzxzxz but my site won't be related to them in anyway. Is this oK? Am I liable for cease and desist?
It really depends on how unique the trademarked term is - if it is a generic term, you are probably ok as long as your usage has nothing to do with their trademark classification. Of course, anyone can file suit against you if they are aggressive and "think" you are infringing upon their goodwill.
If you are talking about a site name like: alliphones.com or something like that.... iphones being the trademarked word... Many times, companies will not send a cease and desist unless it's directly effecting them as a competitor/slanderer/etc. If it's simply a fan site, you should be safe enough.
No need to be worry about that. Almost every site have their sitenamesucks.com and there's nothing they can do, even if it is directly related in a negative sense...
Except sue you if they're aggressive, as mjewel suggested. There's nothing to stop someone with deep pockets to run you down on legal costs to get what they want. Google around for the fallwell.com dispute. The registrant eventually won, but you could see what he went through. They can also file an administrative proceeding for the domain name, and win if you don't reply at all and they meet all the conditions. You can find a hint of that proceeding in your registrar's legal agreement. My point is if you insist on registering a domain name that contains a term or phrase matching a trademark, make sure you know what you're up against.