Caveat ... as I said above, installing an air cooler inside the case is a very challenging task. Trying to get ya fingers in and around in the tight space to plug in fans and retrieve install fan clips can be nigh on impossible, especially in mid tower and smaller cases.
Not recommending this procedure, especially for novices but I'd also add since it was mentioned that I have many times started up a PC to BIOS with no cooler of any kind when doing water cooling builds. Just detached and plugged in stock cooler fan (to fool the BIOS and get it to load) and let it hang there. With no load and the short duration (once I see BIOS screen, I shut down) CPU temps were never a concern. Again, not recommended for 1st time builders and not recommended when OC applied and not recommended for any significant duration.
Approach I use is:
1. Install everything that "won't get in the way" ... PSU, Pump(s) storage, etc ... this generally won't include radiators as MoBo tough to get in and out w/ rads in place.
2. Boot up system "on air" with stock coolers on CPU and GFX cards .... install OS, make sure everything works and nothing has to be RMAd
3. Take out MoBo / CPU / Stock Cooler / GFX Cards and install rads
4. Install WBs on GFX cards
5. Install MoBo / CPU / GFX cards and connect all cables as required. Boot to BIOS screen and shut down after confirming operational.
6. Install CPU Water Block... boot again to BIOS (reason i added this troubeshooting a users build, found out that he had over tightened the clamping mechanism and one or more CPU socket pins lost contact w/ CPU.... backing off screws just a bit solved issue.
7. Install / Test WC system:
a) all tubing / fittings ... took about 4 - 5 days on last build with rigid acrylic tubing
b) fill / static bleed system ... 2 hours
c) dynamic bleed and leak test system ... pump only on ... 24 hours duration, open bleed valves fill as necessary after 1, 2, 4, 8 and 24 hours.
8. Boot and test system ... start working on OCs.
If not obvious by now, when ya spend as much as a week installing and testing the WC system, there is significant value in doing the quick test to see if BIOS loads. Cause after a week of effort ... no fun draining the system, uninstalling all the water cooling stuff to figure out where the problem is, fixing it and then re-installing everything.
Obviously, a CLC is a very different animal and no need to go that route with one ... I would keep a spare tube of TIM around tho in case it does have to come out and breadboard to find the problem.