Also, this is my first time getting to 70+ dwarfs in a fort and I'm a bit overwhelmed with trying to designate labors. ...
I'm kinda lost as to where I should have my guys allocated.
... so how do I manage this many people?
I cannot tell you how highly I recommend Dwarf Therapist, found here -
http://www.bay12forums.com/smf/index.php?topic=66525.0After you download that, start your DF game, then start DT. Upper left corner, connect to DF, then read dwarves.
The utility will then pretty much introduce you to each dwarf in your fortress, in a spreadsheet like fashion. You can see their skill levels and which labors are turned on, and you can quickly change that with a click.
Wait, you might say, there's a lot of labors and a lot of dwarves, so that's still to many clicks! You'd be right, so decide what 'common' patterns' of labors you might want to play around with and make one dwarf have that pattern of jobs, then right click on that dwarf's name and designate a job title based on them. This allows you to highlight any or all of your dwarves and set them to that pattern with a click, then if you wish rehighlight them and reset them to their previous job title, without changing their duties again.
Commit pending changes to make these things become set into your game, or clear pending changes to start over if you need. Continue to use read dwarves to see how their skills are changing over time, and make any large or small changes to the labor designations quickly and easily as you see fit.