Summary: (The book of Psalms is a collection of sacred Jewish poetry; the authors are somewhat anonymous, though a great many were written by King David.) The author sees those who follow wicked ways, and how their way leads to failure upon being unable to withstand God's judgement; he contrasts that with an ideal of studying and living out God's Word, which nourishes like roots close to water and bears fruit.
Response: Yup, going to the biggie. The psalmist does talk about eventual fates, but the big thing in my eye is that failing or bearing fruit is the normal action for the two groups. I know I'm not always a failure, but I want to keep rooting myself in God to be nourished by Him, to do His work.