CSS allows you to format everything, practically. You should be able to modify the page breaks and length between posts by using margin, padding, line-height, etc.
If you don’t mind shelling out $40 or so for a couple of books, I would highly recommend buying CSS For Dummies and CSS Zen Garden. The Dummies book will give you a very good grounding in CSS, while Zen Garden will show you what is possible with the technology.
