need help with money exchange

[mountainmama]

hey guys...
i'm leaving for europe in three weeks for a month. i'm going to two places that aren't 'euro-fied'--the uk and the czech republic. what's the best way to save money while accessing it and exchanging it? i had planned on using an atm, but i have a few questions.

first of all, i know this may sound stupid, but when you take out cash from the atm in a country, does it spit out euros? if it does, do i then face the exchange rate of my bank plus the conversion rate? if not, what's the best place to exchange money? what is a decent conversion rate?

i have $3000 for this trip. should i take it all with me in traveler's cheques?

thanks for your help...
katie