- Neither information nor knowledge are plural nouns.
- Information and knowledge is not plural. It's what is called a "coordinative noun phrase".
- Generally, the grammar of coordinative structures is a complicated topic. These kind of noun phrases can be treated as either singular or plural, depending on whether you view them as one thing or two things.
Examples of coordinations seen as separate (plural):
- The House and Senate are in conflict. (not: is in conflict)
- The bride and groom have left. (not: has left)
- Research and development are not the same thing. (not: is not the same thing)
Examples of coordinations seen as one thing (singular):
- The wear and tear is not a problem. (not: are not a problem)
- Research and development is expensive. (not usually: Research and development are expensive)
Often, both interpretations are possible:
- The snow and ice is melting.
- The snow and ice are melting.
- Is crime and violence more prevalent today than in the past?
- Are crime and violence more prevalent today than in the past?
Most means "the best part of". It doesn't really make sense to talk about "the best part of" two separate things, so constructions like "most ... and ..." will typically dictate a singular view of the coordination:
- Most crime and violence is caused by poverty.
The same goes for all, a lot of, etc.:
- All this buying and selling is getting us nowhere.
- A lot of education and training occurs outside of schools.