3D ARTIST

I use 3DS Max, and thats basically the same, if you're using the standard material editor, just pick an unused sphere and click the box next to diffuse>bitmap>pick a file> apply to selection by clicking the green button on dragging to it.  Then if you need to, go to view> view materials in viewport and choose the 4th option

I use maya which requires use of a UV editor and when dealing with polygons. UV's is a must when trying for correct placement of the Texture... That being said if it is a simple model and texture placement does not have to be exact, you should be able to open the texture editor, click on one of the materiel nodes (should be six spheres in the editor) click on one... which will give you a dropdown menu inside the editor... click on diffuse then another window will open click on bitmap and chose the file location for the desired image. load that into the node you chose(sphere you clicked earlier) it will load and give you a preview.. drag and drop that to your model. if you cant see the image you will have to enable it in the texture editor. There is a button that when you hover over it with the mouse cursor will say show standard map( or simular. This will allow you to preview textures applied to your model without rendering it. hope this helps.