Avoid John Patrick like the plague.
Gunther,
fortunately you came to this site. John Patrick's books are absolute drivel. His own advice is self-contradictory and he is basically a snake oil salesman.
For that matter, avoid Jerry Patterson, Clifton Davis or any book which makes the bald, unvarnished lie that "Card counting doesn't work."
Yes, you want to crank up the bets when the count is high. The higher the count, the better your odds. The better your odds, the more you want to bet. If you make bets when the odds are in favor that are a good degree larger than the bets you make when the odds aren't in your favor, you will come out ahead.
Any book which claims to help you beat the dealer that does not operate on the principles in the paragraph above is smut.
So to answer your question, how much do you need to swing your bets, I can only tell you is that "it depends". On a one-deck game, your high bet needs only be 4 or 5 times larger than your small bet (so you might bet $5 until the count is high, then bet from $10 to $25 depending on how high the count is, when it is high). The more decks you have, the more you need to spread. Up against two decks? 6-to-1 or 8-to-1 is in order. Four or six decks? At least 12-to-1.
Welcome to the board and if you have any questions, feel free to ask. You sound like a smart enough guy to sort the wheat from the chaff.
M.