I prefer to use veneer with the 22.2mil bubble free backer from Qakwood. I bends around the rounded over edges smoother and easier than the 10mil paper backed veneer. Also, minor imperfections in the cabinet don't telegraph through the 22.2mil backer.
Like Jay, if I have rounded over the long edges of the front baffle I wrap the veneer around the sides and front in one piece. The back, top and bottom are three separate pieces. If you are planning on wrapping the veneer around edges like this, then the iron on method is a good way to go. I use the Heat Lock glue since it is formulated for this purpose.
The order of application I use is to apply the back first, then wrap the side-front-side, then do the top and bottom (it doesn't matter which one is done first). The reason for putting the back on first is that when you apply the wrap around piece, the seam is not visible from the sides. The reason for putting the top and bottom on last is that when you wrap the veneer around the edges there might be some small gaps. If you try to force the veneer down you will end up with dimples instead of a smooth radius. If you do end up with a small gap it can be easily filled. Then when you apply the top and bottom the repair is covered up and everything looks good. It you put the top and bottom on before you wrap the sides that small gap will show.
Here is a link to my N3TL build thread. Scroll down to post #47
http://www.audiocircle.com/index.php?topic=120896.40Here is a link to info about the heat lock glue
http://www.veneersupplies.com/products/Better-Bond-Heat-Lock-Veneer-Glue.htmlAnd here is one to a bunch if information on veneering, topics are in the left hand side bar
http://www.joewoodworker.com/Whichever way you go, practice on some scrap first.
Mike