Step one is clear an area where you can dry your wet paper whether these are books or single sheets.  Choose a place that has good air circulation.  Use electric fans for this and let these oscillate.  This will hasten the drying process and discourage the item having molds.   Take note that if you put the paper to dry out in the sun, some fading of print may occur.

For maximum results, insert tissue/ plain newsprint or paper towels in between every few pages.  For books, don't overdo this step as it may become deformed.

In some cases, the only way to save a book is to freeze them while they are wet and dry using vacuum freeze drying.  You can also do this if you don't have time to attend to your books yet.

Check out this website for more detailed information.