I think it’s a measure of the distance between two genes, they don’t necessarily have to be adjacent genes.

I’m not a geneticist, so I could be wrong, but my understanding is that two genes separated by 1 map unit on the same chromosome segregate 1% of the time. At every meiosis, there is some chance that there will be a cross-over event between two genes such that they segregate. The physical separation between close genes makes it much less likely that they will segregate compared to genes at opposite ends of the same chromosome, or on separate chromosomes, so you can map the relative separation of genes based on segreation frequency. The physical "size" of the map unit in bp will be different for different sized chromosomes.

indeed. One centimorgan represents a 1% frequency of recombination. there is no connection between this and the physical distance between the genes. For example, because genes at the end of chromosomes tend to be transmitted together, genes appear to be "clustered" close to one another at the end of chromosomes.
However, linkage maps must not be underestimated. They do give the order of genes on a chromosome, and were the first step to sequencing the human genome.

What does the question have to do with genetic counseling?

I’m going to assume this is just your play on words. 🙂

i think he meant that he needed someone to counseil him on genetics 😉

Yep, that’s what I figured.