First of all - Wow! Didn’t God to some amazing work when He created us?! What a wonderful designer He is.
"For You formed my inward parts;
You wove me in my mother's womb.
I will give thanks to You,
for I am fearfully and wonderfully made;
Wonderful are Your works,
And my soul knows it very well.
My frame was not hidden from You,
When I was made in secret,
And skillfully wrought in the depths of the earth;"
Psalm 139:13-15
It is fun and easy to make learning about the senses very "hands-on". There are many resources available online and at your local library which describe how each sense works. Included below are a few ideas we used in our co-op class and links to the rest. Anything in bold should be "clickable".
SIGHT
The ability of our eyes to see.
1. Explore how important sight is to us by removing it! Children can be blindfolded and then lead around by a sibling or parent. When being led around how confident were they in their leader ? Was it difficult? How does our sense of sight help us in our everyday lives?
2. They can also explore their own bedroom without help (but with supervision and instruction to move very slowly so as not to get hurt). Was it easy to find their way around a familiar place without the sense of sight?
3. Thank God for the sense of sight.
Explain that those without the sense of sight rely on their other senses. Those who are blind or visually impaired need to use their sense of touch to read (braille).
Links to more ideas:
Lesson Plan about the sense of sight for elementary ages
Parts of the Eye
Sense of Sight
SOUND/HEARING
The ability of our ears to hear sounds
1. There are a lot of hearing activities at the below website. I won’t waste time typing any ideas out beacuse they explain them very well:
Hearing Activities
Also see: Lesson plan for sense of hearing
About the Ear
2. Thank God for the sense of Hearing
TOUCH
The ability of our hands and skin to feel the things around us.
1. Have a number of similarly shaped objects for the kids to touch. For example: orange, bread roll, peach, apple, tennis ball. Blindfold child and have them touch each object and try to identify it.
2. Also have them use other parts of their body to touch the object. Can they feel as well? For example, touching an apple with your elbow will feel different than exploring it with your hands.
3. Thank God for the sense of touch.
Also see:
Lesson plan exploring the sense of touch
SMELL
The ability of our nose to smell.
1. Place different items in brown paper bags and have children smell each and guess the bags contents. Some fun ones we used are: vanilla, peppermint tea, chocolate chips.
2. Explore how smelling and tasting go together.
Pour a small amount of apple juice into a cup and grape juice into another cup. Have child pinch their nose and take a sip of each, drinking water in between to wash their palette. Can they identify each juice? Repeat with nose free. Is the taste stronger and easier to identify?
3. Thank God for the sense of smell.
Also see:
Sense of Smell
Lesson Plan exploring the sense of smell
About the Nose
TASTE
The ability of our tongue to taste.
1. Label tongue diagram showing how parts of the tongue taste things differently (bitter, salty, sweet, sour).
2. Identify foods that taste in these different ways:
Bitter - Cocoa
Salty - Salt
Sour - Lemon
Sweet - Sugar
3. Look at each others taste buds with a magnifying glass!
4. Thank God for the sense of taste.
Also see:
About the Tonuge
Lesson Plan exploring the sense of taste
More Online Resources for ALL 5 SENSES:
Fun Lesson plan incorporating the 5 Senses using Popcorn! Also includes good definitions of each sense.
The 5 Senses Working Together
Neuroscience for Kids - - Lots of stuff! A whole section on sensory systems
Experiments For All Five Senses
Neuroscience for Kids - The 5 Senses
Five Senses Activities for Pre-schoolers
Student Designed Website about the 5 Senses
Fun books with hands-on experiments about the human body:
Janice VanCleave's Play and Find Out About the Human Body: Easy Experiments for Young Children 
Science and Your Body (Science Activities) by Usborne Books
Other books we have enjoyed:
Usborne's Flip Flap Body Book - Part two is titles How Do Your Senses Work? My daughter loves this book
What's Inside You? (Starting Point Science) - Also by Usborne (Maybe I should become a consultant!)
First Encyclopedia of the Human Body - Another from Usborne | 
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The Human Eye. What a magnificent creation! So complex, so useful, so intriguing.
