Hi Grace,
I am pretty new, as well, but can share some experience.  We live in northern michigan in a forested area.  We have lots of ticks and other bugs in our property.  So we heard from neighbors that Guineas would be part of a bug-out solution.  Therefore, when we ordered our first batch of chicks we went wide-spectrum on the types of birds to include.  We got two guineas, a turkey and several hens from a couple of different breeds.  Everything was ok in the first year but in year 2 the now mature Guineas were displaying lots of non-neutral behavior.  One of the Guineas was the dominant of the two, then tried to be dominating the whole flock.  It was agressive, pecking laying hens, and (as we had been warned) very noisy.  Also we did not notice any appreciable reduction in ticks on us, every day. (We have been told this is a particularly bad tick year.). So one morning my husband got really distraught about our other hens being pecked and chased ... so he eliminated the agressive Guinea.  Then her 'sister' Guinea went through a period of grief and loss and new levels of non-stop calling.  It was sad and I was not sure it would ever end.  Eventually it levelled out.  She still has moments but is sort of OK.  However, she is definitely more agressive than laying hens.  We are watching and waiting.  I was feeding the flock some meal worms from my hands and the Guinea bit my finger so hard it drew blood.  I am fine 

.  But it makes me feel her days may be numbered as well.  I am not sorry we got the Guineas, but would caution anyone considering it.