GATe examination is conducted in 23 disciplines/subjects. However, the candidates are allowed to appear in only of the subjects. Therefore, first of all, the author should decide about the subject in which he intends to appear in the GATE examination.
The website address of GATe 2017 is - http://www.gate.iitr.ernet.in/. Though the author will become eligible to appear in the GATE examination only after completing the degree or while studying in the final year of the degree program, he may visit the website of GATE 2017 to know the basics of the GATE examination.
Civil engineering is listed as one of the subjects of the GATE. Since presently the author is studying in the first year of the degree program, he may focus fully on his degree syllabus without bothering for additional books. Clearing fundamentals of all subjects taught in the degree program will help in clearing GATE examination also.