How to organize your release tests

In the company where I work we have major releases twice every year. Extensive testing (automated and manual) is done the weeks before.
The automated tests produce logfiles, the results of the manual tests are written down in test plans (Word documents). As you can imagine this results in a lot of different files to be managed and interpreted by the test engineers.
How do you organize your release tests?
E.g. Do use a bug tracker? Do you use any other tools? How do you specify what has to be tested? Who does the testing? How is the ratio developers / testers?