First, toss the cookbook and come to the forum for your info.
Next, learn to use the search/find function at the top of the page.
Next, read
Smokin's BBQ Guides (101s) for whatever it is you are smoking.
Next, when you post a question like you did above you need to give all the details you possibly can - your smoker, the meat, its weight, wood used, how long was the cook, did you go by the hour or shoot for internal temp of the meat. You really cannot give too many details.
Lots of good folks here to aid and assist. We can't help if we don't know what you did in the first place.
This may seem like a chiding but it's not
We want to help but need more info and it's always good for a noob to try to find it, read it, then ask questions.
So, tell us about your smoke
in detail and we'll get ya headed in the right direction!