I'm going to have to dissagree with the people that say you should never cut off leaves. Generally you don't want to cut leaves, but there are times you must:

- if there is mold on them (fix the cause of this soon)
- if there is a concentration of spider mites on them (fix the cause of this soon)
- if they are so old and yellow that the plant cannot benefit from them any more. At this point you are only shielding light and inviting disease and mold. This is completly normal during flowering and around the bottom during veg.
- if you cannot sufficiently bend them out of the way when they are blocking the light from a bud during bloom.

And that's da truth.