You can register a delegate on 4th January, the entry cost was set at 20 million XCASH but due to demand, that cost has estimated to have risen to over 500 million XCASH-- market forces at work. You can still vote for a delegate (set at 2 million xcash per vote). Each delegate sets their own rewards, so you'll have to look for the best deal. You'll be able to vote through the X-BANK in the very near future, but in the mean time you can use the CLI or android wallet to vote.