A Starcraft 2 Beginner's Guide to Protoss

Protoss in Starcraft 2 are significantly different from the other races in a number of ways, not all of which are important to the discussion here. If you are a bronze or silver ranked player you are doubtless familiar with the barebones basic information regarding the race: Protoss use shields, need pylons to create buildings, and do not need their worker units to stick around in order to construct things. If you've got all that but wish are struggling in the lower brackets of 1v1, here are some important considerations to keep in mind:

Cybernetics Core
If you are familiar with the original Starcraft, you are aware of the importance of the Cybernetics Core. However, in Starcraft 2, the necessity for a Core is exacerbated by Protoss' arguably coolest ability: the Warp Gate. Warp Gates are what allow Protoss to keep up with the rapid build times of the other races and prevent them from getting overrun by allowing units to be warped in anywhere, with a low cooldown. The upgrade itself is cheap, but it takes a fair bit of time to complete. Whereas many builds from low level players will focus on going with multiple Gateways (not necessarily a bad idea), if you are to compete past five to seven minutes in the game with production, Warp Gate research will be required. This means building an early-ish Cybernetics Core. A typical build will consist of a Pylon, then a Gateway, followed by a Cybernetics Core. This concept of the early Core not only allows for the research of Warp Gates, but also paves the way for Sentries and Stalkers, the other bread and butter units of the race.

Micro
Protoss are probably the most micro taxing race. For those not familiar with the term, micro refers to your ability to control the individual units and has nothing to with building timings or placements. Early game rushes against Protoss are common because their unit production does not kick into high gear until Warp Gates have been fully completed; as a result, a player needs to familiarize themselves with all the early game units. Know their strengths and weaknesses, know that zealots have to be in melee range, and know that stalkers are one of the fastest units in the early game. Know how to utilize the Sentry's abilities to their best effect, and know that Force Field combined with Zealots are great for killing ranged units like Marines and Marauders. The best way to practice this would be to start up a 1v1 against a low level computer and just practice controlling the units. Try to build traps for the enemy with Force Fields and try to get a good understanding of where to position your units.

Choose a Tech Path
Many low level players will want to get one of everything: Carriers, and Dark Templar, and Colossi. Protoss are an expensive race and it takes a lot of money to develop their technology. Choose, at the beginning of the game, which path you want, either Robotics Bay, Starport, or Templar tech, and stick to it. If the game goes on for a long time and you find you have lots of money or that you absolutely must build something to survive (for instance your opponent has cloaked Banshees and you need an Observer), then feel free to switch. Otherwise, however, stay true to your path. If you deviate, you will find your army is too small to compete with the other because you invested in buildings rather than units.