Doctorofcredit.com is the best blog for that. Data points on all sorts of aspects of the bonuses (hard hit? What counts as a direct deposit?) and usually a rundown on the specific bonus you’re looking at. They maintain a monthly list of the best bank bonuses so I would start there.
Tips:
SPREADSHEET. Make it now. Bank, opening date, date to close, bonus, bonus posting date, bonus requirements, fees, fee waiving requirements, 1099 received Y/N (yes bonuses are taxable income), misc notes
Details. Details. And I’m gonna say it again, Details. You have to know the details of every bonus and you have to keep track in your spreadsheet. If you don’t do pesky details this is not the hobby for you. (Yep, it’s an actual hobby for some of us! You can have all the bank accounts you want if you can keep track of them. And just because you hit the bonus doesn’t mean you start moving your actual banking to them

)
This is ALL spot on.
I wasn't good with spread sheets but kept a Word document with every detail in it. The date I applied, what promo code I used, where the opening funds came from (cc, savings acct. etc.) when/how I attempted to trigger the bonus, what worked/didn't work, when/if I actually made changes to my DD at work, if I had to mail back a signature card, where/when I mailed that back.
I took screenshots of many of the application steps, esp the page that shows the promo code entered where it should be. (Don't even try to tell me I didn't enter it!) I also kept track of the steps taken to keep the account fee-free such as DD of $500/month, when bonus posted, when I could close account without penalty and when I'd be eligible for another bonus.
I wasn't always this anal about it but so many instances when I'd look back and wonder if I really did follow a particular necessary step or did I neglect to do so?

Lack of recorded details early only leads to later frustration.
None of it is difficult but if you're churning mulitple accounts, it all gets to be a blur. At one point, I had around 8 checking accounts under one log in with M&T in my name, dh's, and our 2 adult kids. That is 24 checking accounts just with M&T.

It was rare to only deal with one bank at a time but M&T was a gravy train.
The bonuses for our kids went to either their student loans or car loans, so they were happy to cooperate.
For dh and me, we made around $5k/year combined and we used it to pay off either our CCs or car loan. As pp mentioned, yes you owe taxes on that. Still, would you turn down a $5k raise from your employer simply because you'd have to pay income tax on it? Of course not.
The best one I ever got was $750 from HSBC. The only reason I still remember those initials is because to me, it was saying: Have Some Big Cash.
This was precovid so I don't know how things are these days. I've been taking care of my dad with dementia in my little bit of free time so I haven't been taking on any added chores these days. IIRC, the last time I did any of this was in 2019 or 2020.
Good luck and have fun with it! It's addicting.