beginners defence video?

[brunzenstein]

What certainly many are looking for is a sound video tutorial for bloody beginners getting from a vanilla start as efficient as possible to weapons and ammunition as well as a security wall (automatic produced) around gun turrets for the first small (later to be replaced) factory.

[Bushdoctor]

Well.. It largely depends on how you play and maybe even more on the type of map that you generated. Some people play maps where the enemy is scarce and far away and resources are close,
but others play maps that have opposite features. So there is no clear 'best path' to reach those technologies.
It basically comes down to researching as fast as you can, so you can create the items that you need as soon as possible.
The research menu/tree should help you set a research path in the most efficient way for you personally.

If you're looking for specific builds, like defense walls or anything else, then I would suggest searching among the many available blueprints that you can import into your game.
(Or ask for one if you can't find it)

[Xeorm]

Depends on your playstyle is the problem. Personally I get walls started after red/green research is set up and I can make the new setup for making bricks. Then run it around the base. Setup turrets wherever biters show up, they'll be stopped long enough for me to run over, kill them, and put up turrets for next time. Then run ammo over manually as needed. Only setup a good perimeter with laser turrets, too lazy to setup an ammo line.

[Frightning]

Fastest way to a reasonably secure defensive perimeter is to make some Gun turrets, ammo, and Walls (the researches for Walls and Gun turrets are available immediately for just 10x Red science each, so you can easily hand-craft the science packs needed early on). Place the turrets in a coverage pattern so that the edges of their ranges overlap slightly, and make a perimeter around your starting factory this way, Wall in the turrets themselves (only 12 Walls/turret this way) and they will be highly resistance to being destroyed by Small biters so long as you keep them supplied with enough ammo (e.g. one such walled in turret with no upgrades can easy repulse a wave of dozens of Small biters with only modest damage to a few wall segments). Later on, you can make a proper walled-in perimeter with turrets initially in a coverage pattern along the wall (and later fill in more turrets to increase firepower and safety as needed, though by then, you can really set it up however you want, as you should be able to get the other kinds of turrets and even Land mines with construction robots to automate their replacement).

[Mr. Tact]

It will help significantly if you create your map with a large starting area. This pushes the initial alien spawn points back a bit giving you more time before they become an issue.