Thinner on top and the sides. If you want to hawk your hair keep the top longer than the sides but give it some texture variance. A little cleaner on the back, put a bit of hair in front of the ears, investing in a trimmer is a good idea.
J-list.com has a wonderful selection of male hair products that work wonders called Gatsby. It's for a reasonable price, the amount of product you get seems pathetically small, but you need so little it lasts a long time. The site also has tutorials on how to use each product, it's in Japanese, but you can still see what's happening, and there are plenty of descriptions in the product details (in English). There are also youtube tutorials on how to use gatsby, almost all by Asian guys or cosplayers so the hair styles might be different from what you want, but it gives you a good idea of how to use the stuff.