James read an equal number of pages of his book each night for 8 nights to prepare for his upcoming exam. During this time, he has read a total of StartFraction 6 Over 7 EndFraction of the book. What fraction of the book did he read each night?

To find the fraction of the book James read each night, we start by dividing the total fraction of the book he read, which is \( \frac{6}{7} \), by the number of nights he read, which is 8.

The amount he read each night can be calculated as:

\[
\text{Fraction read each night} = \frac{\frac{6}{7}}{8}
\]

We can express 8 as a fraction:

\[
\text{Fraction read each night} = \frac{6}{7} \div 8 = \frac{6}{7} \times \frac{1}{8}
\]

Now we multiply the fractions:

\[
\text{Fraction read each night} = \frac{6 \times 1}{7 \times 8} = \frac{6}{56}
\]

Next, we simplify \( \frac{6}{56} \):

\[
\frac{6}{56} = \frac{3}{28}
\]

Thus, the fraction of the book that James read each night is:

\[
\frac{3}{28}
\]

Therefore, the answer is:

\[
\boxed{\frac{3}{28}}
\]