Month in Europe

Brussels and Prague need less time than the others. Many people would tell you to skip Brussels altogether. I've never been there so can't comment.

I would not add Italy. As it is, you're looking at substantial travel time since you're covering so much ground. I'd plan to take some side-trips from your existing destinations.

Would you recommend any other locations? I have 25 days to travel and I don't want to overspend any time in one specific city.

You could do something like this:

London 4 nts
Brussels 2 nts
Paris 4 nts fly to rome
Rome 4nts

Florence 3 nts
Prague 3 nts
Berlin 4 nts

Personally I would drop Brussels and add 3 nts in either Venice or Vienna

Considering you need to travel between these cities, you really only have at most 4 days in most of these(if you keep Brussels). Unless you are planning just to do the HOP ON Hop OFF bus, I think you will have more than enough to fill these days.
Also, another way to plan is to look at the Eurail map and see how the routes go. You may pass thru some cities that might be more interesting and on your route already.

Your question is so wide open that is hard to give a specific responses. We cannot write a guide book for you. Any good guidebook will hit the "must sees" very well since they don't change much from year to year. If you don't want to buy them hit your public library and check out all the guidebooks you need and travel DVDs. Spend some time reviewing so that you can get a good idea of what YOU want to see and do. You cannot do it all so you need to some picking and choices. Hang a map and put some pins in so you get a feel for distances. It will be convenient and probably cheaper to get a relatively straight line of travel. Perhaps into Rome and home from Warsaw. In general I would plan three to five nights in each area that you want to see somewhat in depth. And remember that every time you change location you will lose of a day just making the change.

Having limited time i would drop Brussels. In 24 days I would not take more than 6 cities. My selection would be gems of Europe:
London, Paris, Rome, Prague, Vienna, Budapest. Sorry, Berlin did not make it; next time. With adding Berlin, you would have to hurry too much and I would not replace any of these cities for Berlin. By train: London to Paris, fly Paris to Rome, fly Rome to Prague, train Prague to Vienna and Vienna to Budapest. Fly Budapest to Warsaw.

I would not cut Berlin, it's a great city.

No Amsterdam?

thank you everyone for your opinions! & zoe I have already been to Amsterdam before! Loved it very much.

August
2.arrive London
6.train to Paris
10.fly to Venice
13.train to Florence
16.train to Rome
19.fly to Prague
22.train to Berlin
26.train to Warsaw

You are best with point to point train tickets.
Book Eurostar for 6th.
Book trenitalia for 13th and 16th.
Book DB for 22nd and 26th.

You need to drop a city, not enough time for all of them listed. I suggest dropping Brussels.

As of right now and taking into consideration everyone's recommendations:

London- 5 nights
Paris- 5 nights
Rome- 4 nights
Budapest- 4 nights
Vienna- 3 nights
Prague- 3 nights

Hi,

In your situation with a month and based on your last itinerary draft, I would take the night train between Prague and Vienna to squeeze out more time. You may want to consider that as an option.

I am planing my trip to Berlin in August. But I am going to stay there for longer time. Ilive at Ukraine and was triing to look for work at Berlin today. I checked some sites and find couple interesting places at this site https://alphapost.eu, this is the one I trust at the moment. May be you know some places if you trevel there before?

You do not travel by Eurail. There is no such thing as Eurail trains. A Eurail pass is a waste of money. Please do yourself a favor and read the info in this link - https://www.seat61.com/Europe-train-travel.htm.