this tutorial will help you transform your 2d logo into a 3d work of art.
the text version continues the process further then the video one because i ran out of time. Here's
for this demonstration i have selected a random logo form google image search.
1.first clear the scene and goto top view. then in the header of the 3d view click View then background image. click use background image and then click load and find the logo that you are going to use. and then close that window.
2.add a bezier curve and press v to straiten it (make the curve less confusing to work with)and trace around the logo by extruding and moving and manipulating the control points to fit the curve of the logo and once you have gone around the outside press c to make it a complete loop
3.if your logo has separate bits that you want to all be the same colour/hight then simply add a new curve and go around those with the new curve.
4. if you need to put holes in it at certain points simply add another curve and cut out areas(remember to press c once you've gone around the shape to make it a loop. cutting out is genrally easyer in wireframe mode so press z).
5. once you have traced around 1 layer of the logo extrude it in the curves and surfaces panel. you will have to use your own judgment as to how thick you want it too be.
6. if you want your logo to have a layered effect to make certain details stand out then add another curve in object mod and trace around these details.(if the othere layers are getting in your way simply click on them and press h to hide them. when you want to see them again press alt + h)
and you should now have a finished logo all ready for whatever you want.