Solid advice I think here from Ian Hocking on his blog which I've just started reading and am really enjoying.

Thought it might be of interest/help to someone.

http://ianhocking.com/2006/01/approaching-agent.html

Yes, lots of good sense here.

Though I have to say that checking by email that an agency is taking people on won't necessarily insulate you from the rejection that says 'sorry, we're not taking people on'. Many agents are basically full, but don't dare turn away enquiries in case the submission you're offering turns out to be The One.

Emma

it isn't terribly realistic to give each agency an exclusive submission unless you want to hear news of your last rejection via a séance.

well it made me laff...