a couple things to add. i am a new guy myself. if you go the used way take some standards that you can do a rough check of the accuracy. have somebody teach you how to pick out tools that are used.
another thing go to somebody that is in the area that you are in (if you get moved around talk to different people) and compile a list of what they recommend or what seems to be recommended the most.
if they ever have you running a manual mill it might be a good idea to get a few box end wrenches in the most common sizes and use the adjustable end wrench on the sizes in between your wrenches. i have seen that you can get crescent wrenches that have measurements on the side so that you can see what that size is so you can use a wrench and also train your eye to guess the right size (you don't need this kind if your eye is already trained.)
if you use inserted tools that have torx screws get a good quality torx screwdriver set of the sizes that are used. one shop i was at for a month some of the torx screws were REALLY tight and we didn't have one that could loosen them with. luckily there was a automotive place next door that my boss was good friends with and we borrowed a hammer impact driver thing and a torx socket that fit the driver. it worked really well. so it might be a good idea to get the king that will fit a ratchet wrench so you can get some power behind it.
for these mechanics tools i go with craftsman because they will replace them at any store without a receipt no matter how old they are. my dad had a ratchet that quit working and they didn't have the exact one anymore but they had a slimmer design for the profile. these are a good reason to get them used from a garage sale.