Its very much a personal choice, that will change to the most practical as you develop your apiary (ies)
I have a mixture, i have hives on two concrete blocks and a lot more hives on large wooden beams, i.e. a parallel line of two beams, on blocks. This means more per area and good use of the space. You can also slide your hives along the woods supports if you need to move them or do splits , etc.
The main down side to have multiple hives on one single row of wooden supports is that if you do some work in one hive, its pretty likely that the adjacent hive will pick up on the vibrations and before you know it, the hive is already very aware of your presence before you come to work it!!
If your starting out, its probably advisable to keep your hives in singles. Just might make things easier for you.
Nuc yards with singe nucs in, seem to work better if their on wooden supports. Theres less bees generally to have a problem with.
B+ is spot on re choosing a site. You need to avoid lots of overhanging trees and at least try and position your hives so they have some sun during the afternoon or late morning. Its surprising how difficult it can be to find a good site when you know what the right factors are when selecting the area!!
This is my Nuc yard, all on wooden beams. works well in this old quarry site. Not the ideal aspect as its west facing but the bees always get a little sun even in the winter. But its in its own valley with running water only 50 meters away so on balance i love this yard and so do the bees!! I did spend about 80 euros on all theses supports. its treated (autoclaved) pine, which was actually in the reduced section at my local wood store because the beams were warped and bent, fortunately the bees haven't noticed!! I reckon i will get 20 years out of them!! worth the investment I reckon.
http://www.beekeepingforum.co.uk/attachment.php?attachmentid=12533&stc=1&d=1449304978
