The most useful wiki for physicians, this SwitchWiki. In this wiki you can find detailed information about switching from one antidepressant to the other, the same for antipsychotics and how to combine mood stabilizers. You can also calculate the conversion from a benzodiazepine to diazepam equivalents.
Both for the antidepressants and anti psychotics switch tables are made. Clicking on the appropriate switch continues to an explanation and switch schedule with links to Medscape, Pubmed, PubChem, Wikipedia and several other websites for more information. The benzodiazepines calculator can help you switch from one to another benzodiazepine.