There are quite a few places where you can find out your rights by yourself. Unions can give you more detailed advice based on their knowledge of the type of workplace you are in and because they are experienced in dealing with employers.
If you use these sites, take some notes about what your rights are so you can check that your management/employer is following all the correct procedures. They may also help you to decide what questions you should be asking.
The Trade Union Congress (TUC) has a lot of information on its site, Worksmart, that is very useful and covers a range of issues. http://www.worksmart.org.uk/rights/employer_problems.
Also http://www.tuc.org.uk/tuc/rights_main.cfm has links to a whole range of booklets and organisations.
https://www.gov.uk/disciplinary-procedures-and-action-at-work/overview. This lays out a lot of useful details, including suspension etc, over several pages.
ACAS (Advisory, Conciliation and Arbitration Service) aims to improve organisations and working life through better employment relations. It has detailed info and a helpline which can be used by employers or employees.
Health and Safety www.hse.gov.uk. This has the statutory guidelines and stacks of useful info on different health and safety issues.
Equal opportunities: http://www.equalityhumanrights.com/. This has a lot of info including up to date legislation covering this area. This page is for workers: http://www.equalityhumanrights.com/advice-and-guidance/guidance-for-workers/. Northamptonshire Rights and Equality Council provides free discrimination advice and representation to anyone, worker or not, experiencing discrimination. Their service is free and available to people who live or work in Northamptonshire. Contact details on their website: http://northantsrec.org/