I'm planning to watch all 4 of the James Bond rebooted movies series with Daniel Craig in it from Casino Royale onwards (inclusive), but has never seen a single James Bond movie before, so I was wondering whether it is necessary to watch all the previous James Bond movies up until Casino Royale to be able to enjoy it.
No, as explained by Richard when the same was asked of the latest James Bond movie, Spectre:
According to this interview with Sam Mendez (Spectre's Director) he certainly strived to make sure that the film works as a stand-alone piece, without the audience possessing substantial knowledge of the Bond series of films:
MENDES: I love that challenge; it’s a great privilege and excitement to express myself in that way to so many kids. I just hope that I don’t let them down and there are those pressures because at the end of the day, you may make the movie you want, but this is for the audience. And you do pray and hope that everyone believes in it as much as you do, including the kids, and you have to remind yourself every day you’re working on it that for many kids it will be their first Bond movie just as Live And Let Die was my first, and like From Russia With Love or Dr. No were for others. You hope it will make kids go seek out the earlier movies, which are now so accessible to them.
See also this answer to a similar question WRT Skyfall, which points out:
The Daniel Craig Bond movies represent a canonical reboot, in which during the first film Bond earns his 00 status - a part of his history every single other pre-Craig film has been chronologically set beyond.
The Craig films aren't a prequel, they are a total reboot. The first two films (Casino Royal and Quantum of Solace) make a bigger proposition of linking the narratives together, but Skyfall is a direct continuation from this film.
No, not at all. In fact, the Daniel Craig's Bonds are meant to be new unrelated series, kind of reboot. (Not a total reboot because of few details: Judy Dench playing M as in few movies before; if they went for a total reboot, they would cast another M)
It helps though, if you are familiar with Bond's general "trademarks" to enjoy some witty scenes, such as in Casino Royale (first in those series) [SPOILER AHEAD] when the waiter asks him "You want it shaken or stirred?", Bond replies "Do I look like I care?"