The free skill reset you get at L30 only works until L35 though, so make sure you use it before then~

The ones you buy with tears can be used at any level.

Here on nsi you level up pretty quickly so for a "proper shaman" build you can just experiment. You will have reached 30 in no time and will receive a skill reset pot in which you can reset your skills (and even buy for 30 tears at the tear vendor in terminus).

So I would just experiment with skills at the lower levels and get to know what each one does. Everyone has a specific skill build for their class, so there isn't any proper build. It also depends on whether you want to focus on pvp or pve; going into the sage class or the warlock class, etc.

If you do need any suggestions though, ask after you've tested out what you like.