Very often the Nanach are accused of "praying to Rabbi Nachman". This is a very dubious bout of semantics to discredit the Nanach. The word prayer obviously is a reference to worship of God, where as when one asks a favor or any request from a person this is not called prayer. The truth is that real tzadikim do not even speak to other people, they live only with God, when they speak to people they are speaking to the way they perceive God channeled in the way that person is present before them. Most people however, would not consider it blasphemy to ask a favor from a friend or someone with the capability of helping them. Either way, both tzadikim and ordinary people will a ask other people for help. A real tzadik only becomes greater with his death. All the bounty and influx of all the worlds are channeled through the Tzadik, as the Talmud gives one example "the whole world is nourished for Chanina my son" [the Baal Shem Tov explains that the world "for" in Hebrew also means "path", i.e. that the sustenance of the whole world was being in R' Chanina's pipeline]. Therefor anyone with any sense would ask the Tzadik to help him get whatever it is he needs.
In last weeks parsha (portion) - BihaAloascha - some of the wicked found themselves in trouble, so what did they do (11:2) - they screamed to Moshe, Rashi explains their actions with a parable to a worldly King who was very upset with his son, so the son goes to someone his father loves and asks him to take up his cause with his father the King. Chazal (our sages) found no problem with their action, and on the contrary found it sound and proper.