Don't know of a site Tina sorry!!....All I can suggest is that you sow your seed in straight rows with a marker at each end....

Alternatively, depending on what it is you are trying to grow sow into a seed tray and transplant. TinaS are you growing flowers or veg?

Hope this doesn't sound silly but maybe there's a site that shows pics of weeds instead? I'm thinking here maybe of Manufacturers of weedkiller or something?

yes copy and paste this link http://theseedsite.co.uk/

the plant list is here http://theseedsite.co.uk/plantindex.html

btw. how do I put a link in to a question response?

<a href="http://theseedsite.co.uk/plantindex.html">testing</a>

Weatherwise I don't think you can put in an actual 'link' just the url which the person then needs to copy and paste

This is the weed & pest website I tend to refer to:
http://www.bayercropscience.co.uk/content.output/244/289/e-Tools/e-Tools/eTools%20Overview.mspx

If you look into the big gardening encyclopeddias they have a section on weeds. But as been said before go to one of the websites its a lot lighter to kook on line!!!!!! My book weights a ton lol

Thanks for the advice everyone. To Moon grower, I've planted both. Gone a bit mad with the seeds, so I've got a greenhouse full of seedlings (to make matters worse my partner has just invaded it with about 100 dahlia shoots.) Am running out of ground. Thinking of digging up the lawn. Haha.
Tina