Help with mixed between within subjects ANOVA

I've recently performed a mixed between within subjects ANOVA. I have the results for the two main effects as well as the interaction effect.

The interaction effect is significant and I am wondering what to report. Some places are telling me I can also report the main effects whilst others are telling me I cannot if the interaction effect is significant.

I'm completely stuck now and am trying to write up results. I also have other variables where the interaction effect is not significant. I don't know what to report here either.

Thanks in advance.

P.S. I am using SPSS
Others who publish regularly could probably give you a more exact answer with regard to what is required by various formatting styles (e.g. APA style) or journals (e.g. Nature).

From a statistical point of view, though, simple main effects are more enlightening than main effects when there is a significant interaction. I would report main effects followed by simple main effects, or simple main effects alone, but definitely not main effects alone.

When the interaction is not significant, I would think that main effects alone are appropriate.
depends on what you are trying to publish towards and what is interesting. For example, in education, something might be statistically significant but not particularly practically significant. Different journals care about different things. Some might be more concerned with effect sizes rather than p values for example.
You should really be guided by your hypotheses, and report those statistics that are relevant to them. If there's no interactions (and you might choose to use an alpha level of .01, rather than .05 for this), you report the main effects. If there is an interaction, you have to break that interaction down by doing simple main.