Exam for SBI Clerk is divided into three stages-

Prelims of 1 hour duration with following subjects-

1. English
2. Quant
3. Reasoning

Mains is of 2 hour and 40 min duration with following subject-

1. General/Financial Awareness
2. General English
3. Quantitative Aptitude
4. Reasoning Ability and Computer Aptitude

Last one is assessment  of Official/Local Language.

The first and foremost thing required in banking exam is speed and precision.

To follow the first step, you need to practice a lot, solve as many mock papers as you can, along with test series. At the same time time, do not forget to evaluate your performance. This will give you a fair idea about strength and weakness.

The more papers you solve, more grasp you'll have on that subject, this will increase your ability to solve any type of questions that come in exams.

For General Awareness/ Financial Awareness, you have to read a newspaper daily with emphasis on The Editorial part, you can read The Hindu, The Economic Times, The Indian Express. You'll have to well updated with current affairs more so business/finance section regarding this.Newspaper will also help in your English.Do not skip this step at all, as in exams in the recent trends, Editorial parts are coming in either for RC, or some other section.

You may also refer the following books for SBI Clerk Exam-

Quant- Quicker Maths by M Tyra/ Fast Track Arithmetic by Arihant Publications /Quantitative Aptitude by RS Agarwal

English- General English by SP Bakshi or Plinth to Paramount

You can also refer Wren and Martin, that's the best book for grammar. Word Power Made Easy for Vocab.

For Reasoning- RS Agarwal Verbal and Non-Verbal Reasoning

Analytical Reasoning by MK Pandey