Start with the hour, move to the halfhour, then the quarter hour and then intervals of 5 and 10 minutes. Both analog and digital should be learned by children in the first and second grades. All worksheets are in PDF.
 Blank clocks worksheet.
 Telling time to the hour
 Telling time to the halfhour
 Telling time to the nearest 5 minutes
 Telling time to the nearest minute
 Fill in the hands for random times.
 Fill in the hands for more random times.

Fill in the 'digital' times for the analog clocks.
See also Time Passages Worksheets
There are many plastic type clocks that are readily available to help children with time concepts. Providing manipulatives to support concepts support understanding. If you can't find mini plastic clocks, it is helpful to build a paper clock using a butterfly clip. When a child has a clock to manipulate, you can then ask them to show you various times. Or you can show them the digital time and ask them to show you what it looks like on an analogue clock. Time passages are also important to show on clocks. For instance, you can say, it's 2 o'clock, what time will in be in a half an hour. Many hands on experiences lead to enhanced understanding.