If I am a US citizen inheriting a large sum of money from a distant relative, who lived in a foreign country, such as Spain, what kind of taxes and what percent would I have to pay. Also can we get names of US lawyers that would handle a situation like this?

You will pay NOTHING in U.S. taxes on such an inheritance.

You do not need a lawyer.

Sounds like this could be a scam. In any case, you should be sure to report the receipt of the inheritance on Form 3520, Part IV.