So, I really want to do some weapons crafting but I cant find a weapons BP unless I pay a huge amount on AU. So how do you get your first weapons BP? Also, Entropedia does not say what BP's drop from what BP.
General rule as far as I know is that every BP you craft has the chance to drop Blueprints 2 or 3 levels above and below, always in the same category. So you can pick up a Mann MPH or Jester D-1 BP from the technician and start clicking. Keep in mind that to this point, due to the sheer number of 'global' blueprints compared to the NI ones, chances are that you'll loot way more generic ones than local. MA is supposed to be looking for a way around this, to make local blueprints easier to find.
Designating as a "secret newbie benefactor" someone giving useful information on this forum is somewhat unexpected :D
So when crafting armor, do, for example, shinguard bps only drop while crafting a shinguard armor part, or can any armor part blueprint drop?
Any armor part BP can drop as long as it's a few levels close to the one you're crafting, so if you're crafting just for BP's it's best to craft the cheapest one you can.
For example, while crafting Settler Shin Guards on Next Island (Settler Shin Guards are among the cheapest armor parts to craft), you can obtain any Hoplite armor part blueprint ;) It just takes time...