From an article by Robert Godfrey:
To evaluate worship properly, you need to begin with yourself. You need self-evaluation. You need to ask the following of yourself:
How much do I know about what the Bible says about worship?
Who can help me learn more about biblical worship?
Do I want above all to draw near to God in worship?
Do I want to please God rather than myself in worship?
Do I understand my responsibility to worship God with his people regularly?
Will I seek God’s will in worship while avoiding a judgmental and legalistic spirit toward others?
You also need to ask these questions about the worship of any church you plan to attend:
Does this church love and believe the Bible?
Is the worship of this church filled with the Word of God?
How much of the service is given to the reading of the Bible?
How much of the service is given to biblical prayer?
How much of the service is given to singing that is biblical in content and character?
What is the content of the preaching?
Is preaching a substantial part of the service?
Is the Law of God clearly present in the service?
Is the Gospel of Jesus Christ clearly expressed and central in the service?
What is the role of the sacraments in the ministry of the church?
Are there elements of the service that are more entertaining than biblical?
Are both joyful thanksgiving and reverent awe expressed and balanced in the service?