If you are like me and use a current version of Kubuntu (here is what I use), then you might find that D3lphin, which is now said to be the standard file browser, is insufficient in providing the more advanced file-browsing options. For one thing, it doesn't have tabbing, which I use a lot. It also doesn't have a very good built-in search for files. D3lphin uses Strigi, and I haven't been able to get any good search results from Strigi.
When I was using Windows, there was a file browser called Windows Commander (later changed to Total Commander) that did exactly what I needed it to do. It had a split-window option that made copying and moving files much easier. It also came equipped with a very good searching tool to use when trying to find files. Krusader is similar to this utility.