Each round starts with players taking turns bidding on how many points they think they can win that round.
Bidding starts to the dealer's left, and continues clockwise, with each player either passing or increasing the bid in increments of five.
The minimum bid is 80 if you're playing 1s high or 70 if you're playing 14s high. The maximum is 180 or 120 respectively.
Once a player passes, they're "out" and can no longer bid.
When only one player is left (or bidding reaches the maximum), their bid becomes that team's target score for the round.
If they aren't able to collect that many points, their team is "set" and loses however many points they bid.
For example, if a player on team A bids 150, and their total at the end of the round is 145, they would have -150 points for the round.
The non-bidding team always gets whatever score they ended up with.
After bidding is done, the bidder gets to add the five cards from the kitty to their hand, and discard five cards to keep the total number the same.
They can choose any five cards to discard, including any or all of the five they picked up.
Note thought, that at the end of the round, whichever team wins the last trick gets any points that were discarded, so take that into account when making your choices.
The other players don't get to see what was in the kitty or what's discarded.
The main benefit of winning the bid is the bidder gets to decide the "trump" color (no relation).
Any card in the trump color will beat cards from any other color, regardless of their normal rank.
You would generally want to choose the color you have the most of in your hand to give yourself the most benefit.