Lets say you want to store your HTML files in /res/string, then you can use language qualifiers to specify for which language the resources is meant, like /res/string-en or /res/string-nl (for English respectively Dutch files).
Same goes for all other resource types, like /res/drawable, /res/raw/, etc.
For more information checkout the Android Localization pages.
To load the HTML from a string and show it in your WebView use the loadData() method:
html = resources.getString(R.string.my_html_page);
myWebView.loadData(html, "text/html", myEncoding);