1. Read the reading beforehand. Read it again. And again. Ask the priest or someone how to pronounce a word of which you are unsure. Read notes about the readings. Get a sense of what you are proclaiming.
2. Realize you are proclaiming the Word. Be expressive (but not histrionic). Don’t rush. But don’t be so slow that people think you cannot read easily.
3. Keep your finger on your space in the text and look up, make eye contact with your brothers and sisters for whom you are reading. You are helping them encounter God in the Word proclaimed.
4. Use your “thirty foot” voice, not your “six inch” voice. Speak from your diaphragm not your throat.
5. Practice with the microphone beforehand. Ask someone if you can be heard.
6. Enjoy yourself. You are engaged in liturgical action. Don’t act like you’re at the dentist.
7. Realize God is working through you to touch the minds and hearts of people. Pray for God’s help to serve well for the congregation gathered. Vatican II teaches that God’s presence is four fold in the liturgy: in the consecrated bread and wine; in the person of the presider, in the community gathered, and in the Word proclaimed.

There are some really good books available that provide lectors with the Sunday readings, tips on how to proclaim the Word, and explanatory notes. The Liturgy Training Publications’ Workbook, is the best I’ve seen.

Here’s a good website for lectors and the St. Louis University Center for Liturgy is a superb resource.