hello

the best books for nata exam are-

NATA & B.Arch Question Bank  by Ar. Shadan Usmani

NATA & B.Arch complete self study material: entrance examination by  Ar. Shadan Usmani

A Complete Self Study Guide for B.Arch by P. K. Mishra

B.Arch Entrance Examination Guide by Surendra Kavimandan.

hope it helps.

1. Drawing - Most NATA/JEE books are lacking in drawing examples of perspective drawing required for the exam. So, I would suggest you rather go to YouTube for reference. There are lot of videos that discuss various concepts like perspective and colour theory, etc. 
2. Aptitude - This is something you can find in books like Arihant or RS Agarwal (Quantitative Ability). But it is important to be aware of new happenings in the field and industry. Look out for things like venner ads, etc. 
3. Maths - For maths its best to follow NCERT books, as the difficulty level is not that high.