So I have just recently gotten into hunting and have tried to become more aware of calibers, bullet weights, recoil, knowing there is a living animal at the other end of my muzzle. I feel like I have a better understanding of basic ballistics, but I was wondering if there are any resources as to the recommended energy a bullet should be at to humanely kill game? How does bullet type affect this (hollow point, etc.)?

For example, it's easy for me to determine the energy (ft./lb) at any given yardage for a specific cartridge, but how do I know if thats enough? I'm new to this, so I hope this makes sense, and be kind lol!

Read and study this. Best i have ever read: Effective Game Killing
After, on the site the author has many more suggestions on caliber and cartridge. Really excellent site with real world tests and actiual hunting results.

I don’t put a lot of stock in it, to be honest.

.243 used to be too light for whitetails according to popular wisdom. After a half to 3/4 of a century of it NOT wounding deer everywhere, it finally gained acceptance.

Same with .223 until very recently.

If you’re patient and disciplined, you can get humane kills with most centerfire calibers. They used to hunt elephants with .303 for Pete’s sake.

Of course I’m not starving so I don’t rush my shots or shoot at a patch of color through the brush to make sure I put game in the bag. I think the tendency in America is to bring more gun than you actually need, not less.

Bullet energy calculations are cool, but just remember, it's all about good shot placement.
I've had a deer in my scope for 10 agonizing minutes before she presented a good shot, she ran 30 yards and keeled over dead.

I wish this was available in a soft-back

Thank you @boltedsafe, I look forward to reading it through.

^Absolutely this! How many big game animals were killed by the lowly .30-30? Or even older less powerful rounds like the .44-40 or .25-20? Or even a .22 rim fire?

This is a fairly complex question, one that cannot easily be answered in a quick response.

At one time, when cartridges were fairly similar and used very similar bullets, it was relatively easy to come up with simple, broad statements that would be valid in most situations.  For example,  it really didn't much matter if your used a 308, a 270, a 30-30, or  a 30-06....   You went to Walmart, bought a box of jacketed soft points by Remington, Winchester or Federal and called it good.  If it generated 1000 or 1200 ft/lbs of energy or more at impact, you were good to go on deer....

This doesn't hold true as much anymore. Its far more complex...

Take the .300 Blackout.  This cartridge would be a complete non-starter on deer using the criteria outlined above.  Its nota viable candidate using old school bullets and old school technology/loads.  However, loaded with Barnes 110 TSX bullets, it suddenly works far better than it should...

Need another example?  .223 Rem.  Circa 1980, with the then typical 55 basic jacketed soft point and its decidedly iffy as a deer killer.  Same cartridge, same velocities, same energy but loaded with newer bullets and it starts acting far better than it should..

Generally, on deer, using basic unsophisticated bullets, the old 1000 ft'lbs of energy is a good absolutely minimum.  Of course, more is better.  However, there are literally dozens of exceptions now, thanks to improved technologies.   Things like bonded bullets take a kind of sort of minimal cartridge and give it a good boost in performance.

As a rule, it's very important to match the BULLET to the game AND the cartridge.  At one time 99% of cartridges launched a cup and core jacketed soft point bullet somewhere between 2500 and 2900 fps.  It was hard to go wrong.  A 150 Win powerpoint in 308, a 130 in 270 or a 180 in 30-06 worked well.  Now we have very very fast cartridges, easily capable of launching bullets to 3200 fps +++.  Regular cup and core bullets do not do well at those speeds.   Monolithics like Barnes TTSX do very well.  Nosler Ballistic Tips are total failures.

Turn the tables.   Look at something slow, like 6.5 Grendel.    A heavy 140 Barnes TTSX is a miserable choice.  Its too slow.  A Nosler Ballistic Tip is a FAR better choice at 2300 fps muzzle velocity.  In most cases, bullets like the Barnes TTSX totally suck at low speeds.....  BUT Barnes makes a specific-for-the 300 Blackout 110 gran TSX and its MARVELOUS in that application....

See what I mean?  its really really complex.

Sorry, there isn't a really good rule of thumb anymore. Personally, 1200 ft lbs is still a good rule.  There are exceptions.  If this is something of real interest, don't spend all your time thinking about cartridges and spend a fair bit of time learning about the specific bullets on the market.  EVERY BULLET, every single bullet, has a VERY specific operational "window" or sweet spot that it will work very well at.  Slower or faster than that sweet spot and it will not do well....

Colorado hunters ed used to teach 1000 ft/lbs for deer, 1500 ft/lbs for elk.

African hunting lore I've read seems to suggest a heavy for caliber bullet at 2400fps as being the magic formula for great hunting rifles such as the 7x57, 300HH, 375HH, 404Jeff, 416 Rigby among others.