I found the book "The Art of Jewish Prayer" by Rabbi Yitzchak Kirzner, a Judaica Press publication very helpful to some of my students.
I also would like to comment that the practice of giving our children a siddur at the end of pre-1a or 1st grade upon "mastering decoding" of Hebrew reading is wrong and is the beginning of a process that leads to the reason why the klal has difficulty with davening, and why so many of our youth are disengaged with prayer.
Rabbi Mund from Montréal told a group of us at a Torah Umesora summer seminar that the young children at this moment of inspiration and simcha should be involved in a learning process where they write-compose their own tefilah in their native language, which the rebbe or morah translates into Loshon Hakodesh for them to say. I did this the one year that I had 6 first graders in a "backyard camp" program. We under estimate our children's abilities and what they can understand. One child almost composed the entire 1st bracha of benching and included the recognition and appreciation for the chesed his parents do . This is the spring board from which the children should be inloved in learning tefilah. When they see their words in Loshon Hakodesh, they comprehend and recognize those words as they recite their prayer, and they recognize them as they appear through out the siddur with a more meaningful understanding.
