I just reached lvl 50 and really want to reset my skills, because my build sucks:-(
Can someone tell me if its possible to reset skills and if so.. How?
Thank you very very very much!

You can Reset for Zeni till Level 30 , To Reset After that you need either a Green Skill reset book which resets all your skills or a Brown skill reset book which resets 1 SP Per skill

Where/how can I get those books?

the green one from cash shop or in ah but its very very expensive....easily 500kk+ (500.000.000+) on TW s1+

dunno 'bout s2 or hk version....but should be expensive too...

i got my brown one's which resets only 1 sp from a skill via web event from web depot....but i think it's cash shop too..

In SV 2 its 150kk and don't waste your zeni on that just wait for a web depot even , it usually gives brown books - 5

Got a green and 3 brown books on the last event.
Just wait a bit, if u don´t have the Zeni for the Book.