Definitely do kicking first. You need to build the strength of your lower back in order to get the lift. When you are ready to use your arms, you'll know. You'll do it for half a length, perhaps, then a bit longer, Search the net for guidance on co-ordination of arms to legs. In the early stages it is key to get your head in the right place. You may feel a bit like a bobbing turtle. Keep your head down as your arms come in. You may end up a bit low in the water, but your suvival instinct will keep you bobbing up until you become more streamlined.

u go like that wiv ur arms mate (Y) x

This film should help: http://www.videojug.com/film/butterfly-stroke-for-beginners Amber @ VJ

weight training for lats and shoulders; pullups/widegrip ones dolphin kick with kickboard

Butterfly isn't easy. You need to have very good upper body strength, and co-ordination, and that may take a long time to develop if you don't have it. You can practise butterfly kicks in the meantime (with and without a board), and you can practise one arm, other arm, both arm drills, to slowly improve your strength. It might also help you to do a butterfly stroke with a breaststroke kick.