Basic books for GK, English, Maths, Mechanical engineering and Mathematics for CSE preparation?

SUGGEST SUITABLE STD., BASIC BOOKS FOR G.K.,ENGLISH,MATHS and Mechanical engg&mathematics(opt)FOR CSE preparation.
Please suggests me books for foundation G.K.,english,maths and same for mechanical engg&maths(optional) subjects for CSE PREPARATION AS A BEGINNER.

Related UPSC Questions:

• How should I prepare for Civil Services Exam? How to choose optional subject for the same? Is Mechanical engineering a good optional?
• There is no optional subject related to computers in UPSC Mains subject list. Is it a negative point for computer science engineers?
• How should I prepare for the SSB exam of CDS?
• Best reference books for English, GK, CSAT, Mechanical Engineering, General studies & History with respect to UPSC exams.
• Suggest good books for NDA Maths, English and General Knowledge
• Can I do well in IAS Mains (Mathematics) without having coaching for it?
• Suggest good reference books for CSAT, GK, English, General Studies, History and Mechanical Engineering.
• How should I prepare for CDS exam to become an Army officer?
• How many optional subjects should we opt for IAS exam?
• Suggest books for CSAT, Mains (GS, English, Essay, Maths and Commerce subjects).