Your first source of help with your dissertation should be the module descriptor, which is available from OASIS.
The module descriptor will give you some very basic information, such as:
Please read the module descriptor for the precise requirements for your project. If there is more than one section e.g. practical work, report and poster, it is important to keep in mind the proportion of marks awarded to each. The more marks available, the more time you should probably spend on it.
You should also read any handbooks or guides your tutor provides for detailed information on what you are being required to do and what support you can expect. For example, there will be information on:
The descriptor and guide provide important information. These might not seem interesting, but make sure you read them as you get started and keep looking back to make sure you've not missed or forgotten something important.