Hey guys I'm doing a written tutorial about small stuff, that may better your Space Engineers experience or answer some questions. It's not only for beginners, as maybe people who played the game for a while haven't figured out everything. It's very basic stuff, so don't expect too many mind blowing information ;)
1.) Conveyor system: Not an actual tip, but good to know. There are two conveyors, one for only small ships and one for both. This said, there's another difference between them: The small conveyors are mainly for ore mining. Some products such as steel plates don't fit into them, which is why you need the large conveyors. This is used to be called a bug, yet it is a feature trying to make the game more realistic. Construction Components for example are smaller than steel plates. They fit through the small tubes.
2.) Managing inventory: You'll spend an incredible amount of time on your inventory window. While Eve online is called the excel with graphics, Space Engineers is certainly nothing worse than that. Yet, your private inventory on the left is not fixated. You can switch it to the ships inventory by clicking at the small box on the left register. Then it's easy to search the container you're looking for, using the bar underneath, while on the right, you're searching for the item you want.
3.) Leave 1st Person: while building in first person seems the natural way to do, flying a ship that way is way more difficult. Press V to switch to 3rd person, toggle alt key to move your view.
4.) Welder / Grinder Trick: I've died several times due to being "welded" or "grinded". Happens when you set your hotbar to only toggle on and off the machines instead of direct access. For the direct access, go to your "Weapons and Tools" register (Press G -> Weapons and Tools) and take the grinder/welder from there. Now it only toggles on/off when clicking the mouse button. That's annoying but here's the trick: Press your mouse button and while keeping it pressed, open your inventory (or control panel). Release the mouse and close the window again. It'll keep being activated until you press (and release) the mouse again OR (and that's the most important) until you leave the ship. In that way, you can let the welder/grinder run continuously and forget about it. As soon as you leave the ship, it'll stop being powered and you can't get killed by it.