During the summer months, check out 105 Ways to Enjoy Nature With Kids. No matter what you do with your child, whether taking a walk, shopping, or making dinner talk to your child about what you are doing, what you see, hear, smell, feel, or taste. This promotes language learning! It might seem silly at first, but will truly help your child learn a lot from their number one teacher, YOU!
A fun site with lots of crafts, recipes and other fun ideas is live.craft.eat. They even have recipes for homemade 'flubber' and 'play dough' to let your children explore different textures and use their imaginations!
This link lists ten websites where your children can safely play games while still learning important developmental skills. Targeted toward younger children, these sites will help improve your child's vocabulary, listening skills and comprehension (understanding), following directions, and pre-reading/writing skills.