Learn English – How to ask about one’s availability? “free/available/not busy”

Methodology, n.:

1) the branch of philosophy that analyzes the principles and procedures of inquiry in a particular discipline

2) the system of methods followed in a particular discipline

While "discipline" seems to be used to refer to a field of expertise, rather than a particular task, I think you could stretch it to fit. But since you're not really analyzing the methods, and just mentioning them ("general overviews"), I would call the section Methods and not Methodology.

I think either methods or procedures would be appropriate terms, but not paradigms. A paradigm is best described as "a system of assumptions, concepts, values, and practices". Several methods could follow a particular paradigm, for example, but a paradigm is not a method itself.

Check, at least in British English, carries with it the suggestion that the reader should scrutinize the portfolio for errors. Look at is more general. Take a look at is less formal, and could be used in many contexts. Whatever verb you use, your message might have a more favourable reception if you soften the peremptory tone that a direct imperative conveys. You might therefore like to consider these alternatives, or variations of them, depending on the nature of your relationship with the client:

I should be grateful if you would examine the portfolio . . .

You might like to look through the portfiolio . . .

You might find it helpful to look through the portfiolio . . .