In the jungle kayle is a very moderate clear time, moderate sustain champion, for her role there are BETTER junglers. HOWEVER she is an amazing pick when placed against hard carrying enemy junglers that have little early game potential (Yi, Khazix, Aatrox) combat their ability to carry by confronting them early, when counterganking always use your W to MOVE INTO LANE (it's surprising how many kayles waste their w before entering lane and not even catching up to the enemy laner) and DO NOT save your Q it's a slow and applies your passive, it's much more effective to just throw it out as soon as an enemy is spotted. However your late game potential is the best of possibly any other champ in the game, so often the best thing to do is just out-farm the other jungler because you're safe from invasion (low early game potential)
and DON'T underestimate your ability to dive behind a bottom tower with two low champions on it, you CAN double and you WILL escape, just always have a beat on the enemy jungle :)

Kayle top is unbeatable if you're experienced, and only slightly less so if you're new. Pantheon gives you the most strife, but even so he can be countered by hard push and making use of kayle's most powerful mechanic; Kiting. You know the drill, farm, farm, kill, farm, farm, kill. About the most useful peace of advice I can give is that YOU WILL BE GANKED. MERCILESSLY. and not just by jungle, mid will also make an appearance, do not be surprised and do not complain, you picked kayle, it's part of the job description, in the case of hard camp, get some hard counterganks, you will ALWAYS win, and after 6 do not underestimate yourself, in most cases if you're ganked by a jungler who isn't someone with hard cc like udyr, you can kill both the invader and the top laner. And if you do have a bad lane, just farm, play safe, your power is enough to survive till late game and once you're in late game with a good minion farm, it's gg.
Oh and one other thing; ult right BEFORE the whole enemy team jumps you, if you wait till they've got a hold of you, it's over and you won't be able to carry out the fight, have fun wrecking the top lane :)