To find out if you're registered in Collin County and whether your registration has expired, the Collin County elections web site has a voter form that accesses a database of voters in the county. Fill in your first name, last name, and date of birth, and click "Submit". If you are registered, the form will take you to a page with your voter registration card on it.
The voter registration card lists all the precincts and districts you are eligible to vote for. Each district is clickable and takes you to a page with the elected official's name and contact information.
Whether you're going to be out of town or just don't want to wait in long lines on Election Day, early voting is just as easy as voting on Election Day. Polling places will be listed on the Collin County Elections web site. Take your voter registration card and go to the polling place during the times listed.
Early voting by mail is also possible if you will be out of the county during the early voting dates and election day, if you are sick or disabled, 65 years of age or older on election day, or if you are confined to jail, but eligible to vote. Apply to the early voting clerk for a ballot on or before the seventh day before the election, but after the sixtieth day before the election. Be sure to mail in your ballot so that the early voting clerk receives it by 7 p.m. on election day.
The exception to that rule is if you are mailing it from outside the United States -- then you must mail it by 7 p.m. on election day and the early voting clerk must receive it by the fifth day after election day.