Mary,
Wee suggestion. Speak to the person who designed the website for you, and ask him to create a table approximately 55-60% of the width of the screen (centered) and place all pertinent text and graphics within the table...and repeat for each page. Then, regardless of what size monitor is used to view the page, the alignment will be correct, and everything will be centered, and the need to scroll horizontally would be eliminated. Have him download a copy of Netscape, Opera and IE Explorer, and view the completed web pages through each browser just to ensure consistency.