Successful calendar design relies on several key elements. The most important thing you need to remember is to tailor the design to your audience. When you are choosing your images and planning your design you have to ask yourself, "Will this appeal to my customers?" It doesn't matter if your calendar has the correct resolution and size if it doesn't capture the attention of your audience.
Let's talk specs. You will want to contact the printing company you will be working with and find out what technical requirements they have for your files. For our printing company there are two technical specifications that are the most important. The first is bleed. Bleed means that your images will extend an extra 1/8th inch off the page. Let's say your calendar is going to be the size 8.5" x 11". When you design your files the size actually needs to be 8.75" x 11.25". For a more detailed explanation of bleed, check out this article.
The next technical specification to keep an eye on is your image resolution. Be careful when choosing your images; if the resolution is less than 240dpi (dots per inch) there is a chance the images will print looking pixelated. The ideal resolution for calendar printing is 300dpi. Remember, just because it looks good on your computer screen doesn't mean that it will print well. Your computer monitor only displays images at 72-96dpi. An image that is 150dpi will look fine on your computer screen but will print looking pixelated.
Speaking of images, be sure to choose images that will appeal to your audience. If you are printing a school calendar, consider using photographs that were taken at school events like graduation, club meetings, or even sporting events.
Try to imagine yourself as a customer - what images would appeal to you?
Finally, consider the overall design when you are working on your project. What is important to your audience? Do they need information about your organization? Do they need a section of the calendar to write notes? When you start the design work write down the key things your audience wants/needs, then incorporate that into the design as you create your calendar.
Will your calendar be successful? Talk to your printer to make sure you know what technical specifications they will require from you. Be sure to think about your audience when you are choosing your images and designing the calendar. If your audience likes the design and images, they will be more likely to purchase your calendars.