If you are concerned that your child might be exhibiting signs of autism, there are a number of checklists available to help you determine whether or not to seek further assessment. Much information about typical child development can be found on the website of the CDC (Centers for Disease Control) as part of their “Learn the Signs. Act Early” campaign.
The American Academy of Pediatrics recommends a number of different screening tools and checklists that can be used by professionals to determine whether a child should be further evaluated. These are tools for professionals, but you may find the information available useful. A particularly easy one to administer is the M-CHAT(Modified Checklist for Autism in Toddlers) developed at UCONN and available in both English and Spanish versions.