It is important to learn letter first. The children must need to know how to write letters in printable form. After that, they can be taught how to write cursive. Writing cursives is not as easy as writing letters in printable form.
There are many kinds of worksheets available but the best one is still the personally drafted one. This way one can easily check the level of difficulty that is offered to the kids according to their age and even check the progress level. Worksheets can be reused but it is always better to upgrade them from time to time.