The most utile links

http://lineage.pmfun.com
http://lineage2.stratics.com

http://www.ivory-tower.de - check how armor/robe looks at you

http://lineage2.com/ - official site , good to check skill etc.

http://dc.lineage2.com.pl/ - very good if u look for mob/npc maybe in polish but you can change to english ( based on C4)

http://l2calc.l2blah.com/ - very good to check stast with different buffs, dyes etc.

http://l2wh.com/ - very interesting tools: OE, SA, mammon, mannor etc.

http://l2dc.ru/l2data/?t=quest&type=4&lvl=90 - quests for third class, good to fill with stratics informations