I access shared files on my network by using a File Explorer app called FX and the available add on pack that adds network functionality. I find FX is better than the popular ES file explorer, for many reasons, not the least of which is a superior UI. FX can browse a windows network and find shares easily. FX itself is a free download in the Google play store, but the add on pack is 1.99 or so. ES File Explorer is free, though, so if you are just checking out options, it won't cost you anything.