Each task should be estimated for two or three days duration, and tasks which may take longer than three days should be broken down further. Objectives must be clearly set for each iteration and it is critical to track the progress during each iteration. Keep in mind that each iteration has its own analysis, design, implementation, and testing activities.
It is widely accepted that when setting out with Agile Project Planning method, many teams find it difficult to fulfill iteration planning in the fixed amount of time allotted to it. In many ways, iteration planning is a brainstorming session. It is best to first create major tasks and then break them up into smaller tasks and if need be, a small part of that work into still finer chunks.
It is perfectly acceptable for the tasks to be small in size. Creating tasks in the iteration planning meeting is a problem solving process. This is where you do lot of analysis and design work. There will be a need for speedy access to information for iteration planning. A computer with a web browser and access to Google is a a great way to increase execution speed..