Psalm 102 - God is an enduring God. Several times over in this Psalm the writer speaks of God as being here long before anything else was. We can rely on a God who is unchanging. There's a verse which speaks of us! It talks about people who haven't been created yet. Look for it.
Psalm 103 - What are the many "benefits" you receive when you receive the Lord? This Psalm is full of them! Note also the distance our sins are separated from us! Look for that!
Psalm 104 - I like to think of this Psalm as the Psalm of Creation. Praise is given to God for His power to create and then so much of creation is spoken of. It's a great Psalm to sing in the Spring, right about now!