If you're looking up a case in a book, the page number for your pinpoint cite should be easy to find. When you're looking at cases online, things get harder.
Here's an image of a case on Westlaw with the page numbers circled.
Here it is on Lexis:
As you can see, the page numbers are in bold with an asterisk (or two or three) in front of them. Everything after the number is on that page and everything above that number is the page before. For example, everything between the symbol *916 and *917 is on page 916 and everything before *916 but after *915 is on page 915.
Please note that for cases that are published in multiple reporters, there will be multiple page numbers (denoted by a different number of asterisks). The Bluebook will tell you which reporter to use (for this case, which takes place in Massachusetts, it's the N.E. 2d). Make sure you use the pin numbers associated with that reporter, which should be easy to tell from the citation. For this case, the citation is 567 N.E.2d 912 so we want the page numbers in the 900s.
Questions? You know what to do!