Hi, I am by no means an expert, but here goes ..... (based on my experiences with booking flights to USA).

Never been to Delaware, so can't comment on that destination but have booked many flights to USA. I NEVER book through a travel agent, I always book on the internet or phone a flight company from teletext. I generally get 3 quotes to compare. I have booked flights with http://www.airline-network.co.uk and through Asda's website and the link to there travel page. Mostly I have booked through agents from teletext (there are loads of companys on there). You could always try the airline's own website for an idea of prices too. I have found that generally not travelling out/back on a weekend is normally cheaper as I think weekend travel can incur a surcharge but not enitrely sure on that one.

It's probable your best deal will be with an American airline, ie United Airlines, Contintental, US Airways etc. It will depend on where that particular airline flies from whether you get Gatwick or Heathrow - I prefer Heathrow as it's the nearest to me.

As you are more than likely looking at a schedule flight, I would say book as soon as you can. In my experience, the prices rise, not decrease as time goes by. For instance, currently watched the United website for October 08 flights. Not out yet, but they are out upto Sept 08.

Not sure about when would be cheaper to go during July - September. Guessing that most things increase due to school summer holidays???

I have flown with United Airlines, Continental, US Airways and BA to the states. Next one is with American Airlines. I have found all flights to be better than average/good. Seat pitch is always bigger on scheduled flights, food ok, free soft drinks, headphones etc (used to be free alcohol too until recently).

Hope I have been of some help

Thanks for that, (i have also found out that i need to fly in to Philadelphia & not Washington as first thought)