For a tournament announcement, you should look for the following key items:
- Date: can be multiple days
- Schedule: starting time for each round
- Time control: discuss below.
- Format: 4SS or 3RR, discuss below.
- Section: players will be divided into groups, according to rating, or age, or sex, or grade, or combined.
- Entry deadline and entry fee: most tournaments encourage early entry because it's either for them to setup everything, and make adjustment if necessary. There will be a less amount if you pay earlier.
Time control is more complex these days. For large tournaments, there is a traditional tournament time control, such as 40/110, SD/30 d10, which means each side need to finish 40 moves in 110 minutes, with 10 seconds delay, after that sudden death in 30 minutes. The FIDE time control is more common too, such as G/90 inc/30, which means each side has 90 minutes to finish the whole game, but for each move finished, 30 seconds will be added back to the clock. A common time control for shorter tournaments is something like: G30 d5, which means each side has 30 minutes with 5 seconds delay.
Delay means your time will not be reduced until the delay seconds are used. For d5, if you make your move in 5 second, your time will not be changed.
Most tournaments in US are using Swiss pairing, which means everyone will play in every round, pairing against other players according their ratings and early performance. No one will be knocked out. 4SS means 4-round Swiss. Sometimes Round Robin is used, which mean every player will play against all other players. 3RR means 4 players in a group, each player plays 3 games against 3 other players.