Ok, you have a DB85FL motherboard:
This is a micro ATX form factor board. So, you need a case that will accomodate a micro ATX board.
On this site, you will find FOUR pages of Micro ATX cases. You just need to look and see what satisfies your needs:
The above link is provided for your convenience.
So, just microATX matters. I looked at Newegg. Does mid Tower or mini Tower matter?
And this next question touches on another product - the power supply box. Will a Rosewill Photon Series 550W Full Modular Gaming Power Supply fit in a Mid Tower ATX Case?
You want a case that accomodates a micro ATX board. If the mid tower or mini tower support micro atx boards, then you should be fine. You will want to examine the case you select to see if accomodates the power supply you want. This is research you need to do.
Thanks Al.Hill for all the replies. So, I was doing some research and learned that I should choose atx compatible PSU. Now how do I know if 500 W or 550 W or whatever is the power that this motherboard needs?
There is not really much difference between them. Your choice would largely be influenced by the requirements of a graphics card (like amd or nvidia) if you were to use one. If you were to use the onboard graphics, either would be fine. Section 2.5.1 of the tech spec (in the link I provided) advises you on power supply considerations. An excerpt:
"For example, for a high power system consisting of a supported 95 W processor (see Section 1.3 on page 16 for a list of supported processors), 4 GB DDR3 RAM, one high end video card, one hard disk drive, one optical drive, and all board peripherals enabled, the minimum recommended power supply is 460 W.
For example, for a low power system consisting of a supported 45 W processor (see Section 1.3 on page 16 for a list of supported processors), 2 GB DDR3 RAM, integrated graphics, one SSD, one optical drive, and no extra onboard peripherals enabled, the minimum recommended power supply is a 320 W. "
So, unless you get a super-duper, power hungry, monster add-on graphics card, you will be fine with either the 500w or the 550w. If you do go foar a BIG graphics card, be careful - size matters. Depending on your case and the length of the card, it may not physically fit. Also, be concerned about compatibility. However, all of this is only important if you get an add-on graphics card.