The Internet IS your friend.....
Just Google what you are looking for and you will find a wealth of information for free.
For example type in Google: Homebrew antenna for 40 meters
Just browse and read. If you want to know how something works or want to know what the various lengths or heights are for a specific antenna, just re-type your search and you will get plenty of information.
But, if you read through the ARRL antenna book that you purchased, you will be in good shape. Just remember a few key factors.
1. SAFETY FIRST!!!! Always be aware of what is around you, the antenna you want to put up, and if it will harm anyone that could come into contact with it!
2. Stealth, or it really doesn't matter. If you are in a HOA/CC&R situation, there are many antennas and examples out there. If you live out in the country and have plenty of real estate, go for what ever you want or possibly can handle.
3. Keep the XYL happy or find a happy compromise. This should be tied for # 1.
4. And finally, although not the end by any means, EVERYONE knows that an antenna works better when you build it yourself!
It works even better if you do it in horrible weather. (Snow, rain, windstorm, etc.)
Just ask all the other Hams that have gone this route.....
Above all else, have fun and never give up. Enjoy the hobby and try to help others out as you learn more. It really does pay off later on when you may need another hand.
Joe / AJ3O