It would be a complete waste of money sinking it into that upgrade don't bother.
Save it for another day, upgrade your video or GPU, get yourself a nice display, keyboard, mouse... whatever, but don't waste it on maybe 10% performance, maybe.
It's not worth the upgrade, if you have a 4770k. The instruction set is different and their are improvements. But i wouldn't justify paying hundreds on a new motherboard/ and ddr4 memory. Even though skylake is backwards compatible with ddr3L ram. A lot of boards are only ddr4 compatible. It's only worth upgrading if you have a ivy bridge or sandy bridge cpu. Thats where you'll see the biggest leap in performance. Going from haswell to skylake isn't massive. I'd wait at least another year or two before jumping.
Even if you have extra cash to blow and want to get some performance in gaming, i'd say buy a better gpu if anything.
you are probably looking at a 10% boost under optimal conditions. Not really an increase you would notice in the real world. However as Suztera mentioned, you would need a board and RAM upgrade so coupled with those other items, your overall performance might go up a notch. Question is: is it worth the cost? Upgrades like this are seldom worth it when they first come out. If you can wait, the cost of the hardware will drop dramatically over the next 1-2 years.