Roots must be kept moist (not flooded!). Good drainage is essential but at the same time the roots must not dry out. This is particularly important for the first year or more after the camellia is planted.
Mulching helps keep the roots moist and means you don't have to water as often as would have to without mulching.
Use a loose layer of material such as leaf mould, compost, bark, pea straw,etc.
Make sure the mulch is not heaped up against the trunk of the camellia; water and fertilise lightly before applying the mulch.
Watch out for thrips or other pests and, if necessary, spray with carbaryl, maldison, orthene, or some such. Water and fertilise lightly with something like blood and bone before applying the mulch. Always read the instructions on the labels and follow the instructions carefully.
November & December is the time for air-layering in order to get a reasonable sized plant in the minimum of time.