Not bad at all. I've just pointed out the errors for you. I think most are just typos and silly mistakes and I'm sure you are able to fix them as your English is good, but if you need any clarification come back to us. Some of your sentences are far too long, take a look and make the structure clearer. Also, we do not use the euro in the UK , so I have highlighted your ticket price. You need to say £2. Some of these are simple spelling errors too.
Dear Jane,
Hi, how are you doing? I've just received your letter and I've been searching in the internet some information about the place where we want to go next weekend and I've found a useful map.
We have two options: we could cycle round the northen lakes or we could cycle round Lake Windermer. Both of them are interesting but in my opinion, the best option it's the second one because the northen lakes are too far and there is nothing to see. However, if we choose the second option, we can stay in The Queens Hotel next to Lake Windermere, it has a beautiful views of lake, it's bed & breakfast, home-cooked, a bar snacks available at lunchtime at evenings and it's not too expensive.
So I'd start our route round the Lake Windermere from The Queens Hotel to the Castle where we can stop and visit it, it seems a medieval castle, then we can carry on round the lake on our left until Wordsworth House, it seems a beautiful house next to the lake where we can eat something and have a rest, then we carry on to Streamboat Center where we can see boats and we can talk to somebody who know about what kind of boat they use in the lake. Finally, we'd arrive at Beatrix Potter Museum. There we have to pay a ticket if we want to enter, only about 2€, it has a very interesting colections of pictures. And then we'd arrive at Queens Hotel.
I hope this suggestions can help us.
See you next weekend.