How to record sales tax

[Carl Flippin]

I understand that, when selling, one must keep sales tax in a seperate
account to make paying sales tax easier. In the case of purchases,
however, is it better to just include the sales tax as a part of the
expense or should I have a seperate sales tax expense account?

In case it is not clear, I am a noob to accounting in general. Is
there a good book to learn best practices for accounting in personal
finances?

Thanks,
Carl Flippin