You can get the Mothers Clay Bar kit at any auto parts store or Walmart. Just get some decent car wash solution, don't use dish washing liquid. Pick a wax you like. None of this has to be expensive. Main thing is to keep your wash mit clean. Same with the clay, if you drop it, don't use it! Like I said earlier, there are lots of options and opinions out there, use the one you like best.
Take a look at this wax, it is for blue vehicles. I use it and it works well. Any carnauba wax will do though. Don't use circular motions though with the dark paint.
http://poorboysworld.com/natty-blue.htm