Can I conjugate the passive voice in any tense other than the present?

The passive voice has got me tied up in knots. My professor's site said that estar + participle needs to be used in certain cases, but I couldn't understand those cases. Does it follow the same rules as ser vs estar in the indicative?

The passive voice has got me tied up in knots. My all-spanish workbook refers to ser + particple as the formal technique. It then recommends two other forms as more common. The first is called 'se' en frase pasiva, and is se + verb in 3rd person singular or plural. However, there's also a section for a 'se' impersonal where it's se + verb in just 3rd person singular, and I can't for the life of me tell what the difference is between these 2 se + verb options?