When picking a motherboard, your first priority is to make sure it has the right socket to match the CPU. Intel offers the new 1151 socket. Regarding AMD instead we find the socket AM4 (for the Ryzen CPU) and the socket FM2 (for the APUs).
The second priority is the motherboard chipset. For Intel we find: Z270 (socket 1151) - is the best of the best, but it is relatively expensive, so it is recommended only to those who overclocks or is interested in Crossfire / SLI. Moreover, unlike in the past, you do not need high-end motherboards to have good results in overclocking, so our suggestion remains Z270 midrange. It is worth to choose the top models only if you need the features they offer. H270 (socket 1151) - is the best choice for the average user: with the exception of overclocking and bandwidth limitations on the second PCI-e slot in addiction to lower RAM frequency support, the H270 offers the same features at a much lower price.
About AMD, between FM2 chipsets the fundamental differences are: A55 doesn't have native support for USB 3.0 and SATA 3, while it supports RAID 0,1,10; A75 supports 4 ports USB 3, 6 ports SATA 3 and RAID 0,1,10; A88X - adds support PCI-e gen3 and new CPU Kaveri. Given the modest price difference, we suggest A88X chipset. With AM4 socket we find the B350 and X370 chipsets: the main differences concern the number of SATA and USB 3.1 ports, with X370 having the best multi-GPU and overclock support. As already said about Intel, for the average user a good B350 is enough, while you can bet on an X370 if you need the extra features it offers.