The Haftarah of VaYakhel is from Melachim, a description of the making of the Temple, which parallels nicely the Parsha of VaYakhel, which describes the making of the Mishkan (Tabernacle).
Linear annotated translation of the Haftarah of VaYayakhel
The Haftarah is very short (to make up for last week, Ki Tisa, which was very long), and on the years that Chanukah starts on Friday night and has two Shabbats, it is also read on the second Shabbat Chanukah. But for a completely different reason than we read it for VaYakhel.
The reason we read it for VaYakhel, since you asked, is here: Labor of Love