Does anyone have a site or link where I can identify weeds? Now that it's spring there are tons of weeds growing especially on my lawn, but I'm not sure what to pull out or leave in. I don't want to resort to weed killers. I don't mind things like clover or other "cover crop" weed staying in my lawn, and I don't mind other weeds staying as long as they don't choke out my other plants or suck the nutrients from the soil dry.

Right now I can tell you about a few of them. One of them has looks almost like a violet with purple flowers. Another one has purple flowers too or purple leaves. Another one looks like a smaller dandelion with several small yellow flowers and serrated leaves.

I'll try to get in pictures sometime, but I wish there were some kind of comprehensive picture guide to help me going