One of the difficulties I've been experiencing as a fledgling gardener is that I don't know what the plants I've planted are supposed to look like early in their life cycles, so I don't know what to weed.
I mentioned this to a friend who suggested that I taste things. (Someone else who I mentioned this to was horrified- "Don't poison yourself!") I found that was a great solution with the herbs, and the onions and fennel. But I did plant several varieties of herbs that I'm not familiar with--hyssop and chervil--so tasting isn't going to help me there.
Because I can't possibly pull all of the weeds out of the entire area, I've started to just pull the ones that I can easily identify, like dandelions. I also went out to visit a friend's farm a few weeks ago and we spent a little time in her greenhouse, where I got some sense of what different plants were supposed to look like. It helped.