Growing from seed

Hi all 

I've grown veggies before from plants and just sowing straight into the ground but this year we've gone the whole way and got a greenhouse and everything so I decided to grow all my own plants from seed

So I have 2 types of tomatoes which I put in a seed tray which has its own lid, I put these near the window in the warm upstairs and some have started to germinate. These are now about 1inch tall so I have removed the lid to give them a bit of airflow but about 60% of the pots still haven't come to anything at all. Am I just being impatient? Will they grow or are they no good as the others have already come up?

Also I seem to be getting all these tiny mushrooms growing in the pots with them, even in the ones with tomato plants in. I keep pulling them out but they keep growing back! Am I doing something wrong?

Thanks x

Ah thats possibly where I've been going wrong, I've been paranoid about them getting dry so whenever they've been dry on top I've been watering them :blink: I might try putting some more in just in case. Thanks for your reply, most helpful.