Different children will have different learning abilities, and also different learning styles that are most effective. Just the simple fact of your involvement will be extremely important to your son in his overcoming this trouble, as involved parenting is vital to successful children, regardless the challenge.
Many schools and pre-schools have resources available to help those students who are having difficulty mastering new concepts. These resources will include one on one tutoring, visual based learning, and even training for parents. Ask your son's teachers which resources are available for you and him, and then take advantage of them. Also, ask the teachers which methods seem to be most effective for your son during his formalized education, and then utilize those at home. The ability to offer multiple methods is also beneficial, as the success of a particular method will vary over time as your child grows and matures.
Finally, your son's pediatrician
will be able to serve as a gateway of information and additional resources, some of which might include the diagnosis of a learning delay, while others will be able to help you cope with the challenges that you face as a parent. Please speak with him or her as needed.