The main reason for me to create this topic was to see if anyone knows how the proportions works, in the square rules, from one edge to another is 5 feet, I would like to know if it is the same with hexes, also, if anyone know any tips on how to create rooms/encounters or scenario using hexes I would be most grateful

I've used both hexes and squares for maps used with minis. Hexes are best used if you use the variant rules for facing and flanking. Outside of that, hexes help with diagonal measurement for movement and spells. Square movement in a diagonal direction can either be 1,2,1,2 or 1,1,1,1. Meaning that the first square moved diagonally is 5ft, the second is 10ft, third is 5ft, etc. So moving 3 squares diagonally is 20ft of movement. Hexes do not need this. Moving diagonally on hexes is just 5ft per square. However, many people using squares just count each square moved as 5ft, regardless of direction. Keeps gameplay simple, and ultimately doesn't give any significant advantages. 

Creating maps and rooms with hexes is where it gets problematic. It all depends on how you make your maps. I use a TV with digital maps that the minis are placed on. If I use maps from the modules, they all have squares on them already. If I make a digital map or find a gridless one online I can overlay hexes using a map program. If you're not doing a digital map, the same problem comes up if you are downloading/ making them to print. This is the main reason I just stick to squares: maps are easier, I don't use flanking or facing, and just do the 1,1,1,1 movement on the grid. 

I find hexes far easier to use. There are some special rules regarding diagonal movement with squares because they're squares. Hexes don't have that kind of problem. Each hex is usually 5 feet in combat. Movement is easy, measuring radius on spells like fireball is easy.

For drawing maps, just draw them, you don't have to conform to the hex shape. Just like you wouldn't conform to squares if drawing a circular room.

Yeah, i feel like that too, my group always complain about diagonal movement (we use squares) so i'm thinking to give it a try

I presume that you already use this, is there any difference regaring of rules? i already know the facing and the flanking rules to hexes, is there any other one that you recommend?

I can't think of any specific rules that apply to hexes but not to squares. The spell effects look a little different if you use the patterns for either hexes or squares. But if you use the clear spell effect templates and lay them on the map you end up with the same coverage. There might be one time out of twenty or more where a certain position would or wouldn't be hit depending on a square or hex map. All in all, no real impact over time. 

One big difference is if you get swarmed, you are surrounded by 6 instead of 8 enemies. 

I never really got into facing. Might work ok in a small group that wants more realism, but has a real chance of slowing things down. I've known a lot of players that want flanking until they realize monsters get to use it as well. I was initially hesitant to do the 111 movement instead of 121, but it hasn't caused any issues so far and sped up combat a bit. (And with 10 players, anything that speeds up combat helps)

I don't use flanking or facing unless the character or monster has special rules for it like Pack Tactics. 

Cone effects are also far easier to figure out.

Basically put, even at normal encounter distances of say 10-12 squares. 10 squares straight is 50 feet. 10 squares diagonal is closer to 70. That's a difference of in range, or out of range for many attacks and spells. It also makes a difference between two normal moves to melee and three moves to get to melee.