Hi Nina,
When my daughter was young I too was worried about making her environment rich for learning so I understand what you mean.
We did use language thoughtfully and a lot, with care in annunciation. We used lots of things 'not for children under 1 yr' when she was one ..same throughout her life. We ignored most labels and focused on our child and what we saw and what we are parents wanted and believed in. She is now quite advanced in language, reading, writing at age 5.
My advice to you is, if you want your son to learn colors and numbers then show them to him. He will learn them. Children are sponges and will learn what you show them. It really is that simple. If you need ideas of what to do:
http://www.ehow.com/list_6364299_ide...year-olds.html
As I mentioned before our main tool was language. We explored the world WITH our child and talked about everything in lots of detail.
Children adore time with their mums/dads. Every interaction is learning. Most likely giving your child a lot without realizing it. The first couple years your child is absorbing everything around him. In fact one theory states the first 7 years are the 'moldable' years and then the core is finished (
http://en.wikipedia.org/wiki/Up_Series). When you are talking to your child, explaining life to him, you are doing something very important (even if it doesn't seem like it to you). There is so much to learn from the narration of life.
Children learn without paying attention also...they might be chewing on a delicious block while you are trying to show them the color blue, but don't be fooled or discouraged. They are listening and before you know it he will pick up that object and say blue.
My daughter was fascinated with flash cards. We would spread them around her and talk about each one. She would of course chew on some and bend them to pieces, but by 1 year old she could name 150 animals.
Just spending time exploring the world (whatever interests your child) together is all you need to do. Yes you might get bored (and that is why the breaks suggested above are great) but you can teach your child about anything they touch/chew on. This is a cube, this part is flat, this part is straight. Let's count the sides. Demonstrate how to drop it, toss it in the air, try to roll it, hide it, find it. It is all language and development.
Lastly, I am quite sure your son will get A LOT more attention and learning at home than in a daycare, even a good daycare. Being a mom is tough work! Don't feel like you are lazy because you are not engaging him all the time, it is not possible. Some of the most priceless moments for a child are just being held close and having the comfort of knowing mum is near.
Enjoy and don't forget to take a break!