The UK Research Councils (AHRC, BBSRC, ESRC, EPSRC, MRC, NERC, and STFC) issued an Open Access Policy in April 2013, which came into immediate effect. In summary, this states:
An annual audit of compliance with the policy is carried out in April each year.
SHERPA, which partners with Jisc, provides services for checking publishers' and journals' OA options, and how these comply with funders' policies. The information they provide may help you choose whether a title is appropriate to publish in. They also maintain OpenDOAR, which maintains a list of repositories you may wish to deposit in.
A key part of publishing open access material is ensuring that readers understand what permissions they have for re-use of the material. The Open Access Scholarly Publishers Association offers best practice guidelines on licensing and attribution in open access:
Beware of predatory publishers who "lie about their business practices for the purpose of attracting paying authors".
With so many publishers out there, choosing where to publish can be tricky. Think. Check. Submit. offers researchers a checklist that will help them decide if a publisher is trustworthy without having to rely on verified lists.