Tu B’shevat is the New Year for the trees and we connect to the Tree of Life through study and blessings on fruits of the earth and the trees.

Zohar Tu Bshevat (Hebrew only)
This is a collection of Zohar and Ari text related to this holiday. Compiled by the Admor of Holmin, Rabbi Shalom Yehuda Gross, Shlita.
זוהר ט”ו בשבט

 

Laws related to Tu Bshevat (Hebrew only)
קונטרס טו בשבט בהלכה ומנהגי היום וחרקים בפירות המצויים

 

Link to Chabad.org with more explanation and blessing guide
http://www.chabad.org/library/article_cdo/aid/615205/jewish/Tu-BShevat.htm