This is the hated Dandelion, one of my favorites. The whole plant is edible even the root. The greens are used to make salad, the root a liver cleansing tea, and the flower can be fermented to make a sort of wine. Most folks just pull up or kill this wonderful herb. They don't know what they are missing out on! When I lived in Wisconsin, I relied heavily on this plant for my green veggies. Dandelions are some of the first things to come up in the spring (even in the snow) and they are still around until late fall, way after your lettuces and spinach have gone to seed. The next one is called Miner's Lettuce or Poor Man's Lettuce.
This one grows all over California and other warmer states. It can be eaten raw or cooked. I like it both ways, but raw is my favorite. It is so juicy and green. It's a welcome treat if you can't buy or grow your own lettuce. It tastes green!
This one is called Plantain. It grows all over the U.S. and southern Canada. There are two kinds, the long skinny leafed one that you see here and the short fat leafed one. Both are edible and taste just about the same. They are best cooked but I have eaten them raw. They are stringy though but I don't mind. The Plantain has been used for thousands of years for wound and burn healing. Some folks say it's all most as good as Aloe on small burns.
This is Yellow doc. This one grows all most every place that is left to the weeds. It gets to be around two feet tall in some places and the "flower" and seed head can reach three feet. They are called Yellow doc because Doc means big leaf and in the fall the leaves turn yellow, although I have seen some turn red or even orange. The seed head is most striking it is reddish brown with lots of oval shaped seeds clustered on the top branches, almost like Rhubarb seeds. For this it is sometimes called False Rye. The big leaves are wonderful cooked and are said to have lots of vitamins and minerals. They are also cleansing and antinflamitory. My Mom used to put the dried seed heads in her dried flower arrangements. The next one is Mugwart. This plant likes to grow in mostly undisturbed wooded or simiwooded areas all over north America. It is in the Wormwood family but less potent. It too can grow pretty tall, up to four or five feet in height. It is used mainly for medicine not for food. I use it to keep bugs out of my cupboards as it is an insect replant. I also use it as an astringent tea externally and internally and as smudge. It's a lot like white and silver Sage. The cool part about Mugwart is that a little gos a long way.
We all know what this one is, Wild Straw Berries! They grow mostly in the woodlands, but some times you can find them in the city. There are a few types, but they are all mostly the same exept for the Alpine Straw Berry that grows in the higher elevations and has WHITE BERRIES! All Wild Straw Berries have little tiny berries that are hard to spot. They are ripe in the late spring early summer and are yummy! That is if you can find them before the critters get them! When you find some don't expect to find many. Most of the time if you are lucky if you find two or three or if you are really lucky a hand-full. It's a nice little treat for those who would bother. I think it's fun to try and find them even if I'll never find enough to fill my pail. 
Ahh! The dreaded Stinging Nettle! One of the best wild things to eat on the planet! Stinging Nettles come in all sizes from just an inch or two tall to over six feet tall! They all have jagged heart shaped leaves a square shaped, hollow stem and lots of "hair" that stings you. If they sting then how do you pick and eat them you ask. Well fist timers want to wear thick gloves and bring scissors or small gardening shears. The best time to get Stinging Nettles is in the Spring or early Summer. They like to grow in moist partly shaded areas. They can be found almost all over north America except for Missouri.. Yep none in Missouri.. I don't know why. I like to get them as often as I can due to their nutritional value. They are some of the most nutritional plants on Earth. YOU MUST COOK THEM BEFORE YOU EAT THEM! Cooking neutralizes the chemicals in the "hairs" that sting you. Once you have cooked them they taste like the best cooked spinach in the world. I have also cooked them in soups, stews, eggs and stir-fry. You can also dry them for later use or to make tea. Stinging Nettle is also used to make a light yellow dye for wool and natural fabrics. After you have been using Stinging Nettle for a while you might find that it doesn't sting you as much any more if at all. 
This is Horse Tail. It looks like this for a few days after it comes up, then it fluffs out and looks really cool. It gets to be up to two feet high or more. It likes moist partly shaded spots. It is used to make a light yellow dye for wool and cotton. It is also dried and powdered and used as an herbal supplement due to it's high silica and mineral content.
As you can see my feet are at home bare in the woods as I hunt for plants. This makes me happy and close to the Earth. I Hope you have fun hunting for plants too. You can find some books at the library and at book stores such as field guides and herbals but there's not too many out there. If you find a good one with good pictures in it BUY IT!! Good luck! Have fun!