Just 3 things. But don't stop there.
Well, a mentor would be nice.
You need 3 tools
A press, because fingers are not strong enough to form metal.
Dies for 9mm because fingers are not accurate enough to form metal to fit.
You need a way to mete powder (most likely a scale, but some use calibrated dippers).
Other tools can wait until you discover the need for them.
Calipers, because not all components you buy are exactly the right size and when you load, you are changing some sizes and need to measure seating depth, etc.
Bullet puller because eventually you will assemble a cartridge you don't want to shoot for some reason.
Other tools as you find the need.
Manuals and instruction books. Lots of manuals. And web sites. Reliable ones, like the bullet manufacturers and powder manufacturers, not someone who doesn't have "skin in the game".
The early chapters of manuals are devoted to "how to load" information and the rest are load recipes. The bullet and powder manufacturers have lots of good advice and load recipes specific for their products. The excellent tome "ABC's of Reloading" has no load recipes, but excellent descriptions of the loading process, written by a selection of different authors.
Casual sources (like forums) are good sources of education and information, but you have to verify everything you find from casual sources.
Remember, only believe half of what you see and one quarter of what you hear. That goes double for what you get from the internet. Even this post. Maybe especially this post.
Do your own independent, confirming research when ANYONE gives you new facts on the web.
Also remember, even the idiotic stuff might have a kernel of truth buried in there somewhere.
I have compiled a few web sites that seem to have some good information (some of which came from me).
Go get a large mug of whatever you sip when you read and think and visit these sites.
For the New Reloader: Thinking about Reloading; Equipment Basics -- READ THIS FIRST
http://www.thehighroad.org/showthread.php?t=238214
which is a sub-thread of this
http://www.thehighroad.org/showthread.php?t=649184
I am looking at getting into reloading for the first time
http://www.thehighroad.org/showthread.php?t=658971
Just bought my first press. Needs some info tho.
http://www.thehighroad.org/showthread.php?t=659358
Considering reloading
http://thefiringline.com/forums/showthread.php?t=488115
Budget Beginning Bench you will never outgrow, for the novice handloader.
http://rugerforum.net/reloading/293...you-will-never-outgrow-novice-handloader.html
Thoughts on The Lee Classic Turret Press
http://www.rugerforum.com/phpBB/viewtopic.php?t=135951
Interested in reloading
http://www.rugerforum.com/phpBB/viewtopic.php?t=13543
Newby needs help.
http://thefiringline.com/forums/showthread.php?t=430391
I hope you enjoy the reading. Thanks for asking our advice.
Lost Sheep
disclaimer:
I do not know you, so if my advice seems over-obvious, take into account my ignorance of your experience level. Also, other readers of all experience levels are reading.