If I take a photo in raw, edit it a little in Lightroom, then upload it to flickr, when I click on the photo in flickr to open it then click on it again to enlarge it, there seems to be quite a lot of detail. When I take the same file to a high street photo printers I am always disappointed. Can I get a print that has the same amount of detail, and if so where?
Viewing size determines visible detail. The visible detail will depend on the viewing size. If you print an image 6x4 inches size, it is always 4 inches tall. Substitute 10x8 inches if you wish, but a print cannot show more detail than its size.
If you view it enlarged to full screen size on your monitor, depending on the monitor, it might be 10 or 11 inches tall. That can show much more detail. And if you zoom in on it larger, to show only half of previous content, the overall total (unseen) size might be 20 or 22 inches then. Much more fine detail becomes visible at that size. Enlargement certainly does help viewing.
We think of digital resolution as pixels per inch. However, there is definitely a limit, and in common viewing situations/distances, our eye cannot resolve more than maybe 300 pixels per inch. If we condense 1000 pixels into an inch (in a small print), our eye cannot benefit from it, we cannot see that detail then.
If you print a photo at "passport photo" size, of course you won't see all the detail that the image holds; it's too small. Solution... print larger. Now, of course I don't presume you are printing at passport photo size, but the logic is the same.
(Of course there are limits - you can't just choose any arbitrary print size, because your image is composed of only so many pixels to begin with.)