Hi ,I have a canon EOS 350D,and i would like to buy a better lense than the kit one.Can anyone recommend a good lense for landscape ,or something to get sharper quality in my pictures ,
thanks Derek

try the Tamron 28-75 2.8 very sharp if you get a good copy

Obviously depends on the money you can/want to spend on it.. more money will usually mean better lens (unfortunately...)
With any lens, make sure you're using a tripod for landscape photography and a remote shutter to avoid as much camera shake as possible.
Not saying that post-processing can replace getting a good lens, but with any lens, some improvements can be made to make your picture into a great picture.. I had a look at some of your images, and you're definately on the right track!!!

The Canon EF 28 - 135mm IS USM is a very nice lens and at a reasonable price NOW also. Bear in mind that it is a EF lens and that will equate to it being a 42 - 202mm on your 350D and if you are looking for a wide angle for landscapes, this may not be quite wide enough. Set your lens you have now on 42mm and this will be your minimum focal length on the 28 - 135mm.
Hope this helps.
Rob

try the Tamron SPAF 17-35/2.8-4 XR DiLD Aspherical [IF], it is good for the film cameras too