niebieski ptak – a blue bird
A careless, irresponsible bum who idles around instead of getting some useful work done, like all decent people do.

z lotu ptaka – from a bird’s flight
From a bird’s eye view, from above.

pisać / bazgrać jak kura pazurem – to write / scribble like a hen with its claw
A not-so-nice way of commenting on someone’s calligraphy. Because hens aren’t known for their hand- (claw?) writing skills.

kura domowa – a home hen
This basically means a housewife, but in a rather pejorative sense – a woman who spends all her time caring for home and children and doesn’t know much about the world. Many women would probably take offence at being called that.

kura znosząca złote jaja – a hen laying golden eggs
This is how you can call something, for example a business, that’s very profitable.

gapić się jak sroka w gnat – to stare like a magpie at a bone
That’s what you do when you just stare at something thoughtlessly. Do magpies really stare at bones? I have no idea.

trzymać dwie sroki za ogon – to hold two magpies’ tails
To have too many irons in the fire. It implies that multitasking is bound to be a failure, because, well, go and try catch two magpies by their tales…

rządzić się jak szara gęś / szarogęsić się – to boss around like a grey goose
That’s what you do when you think you’re the most important person in the world and expect everyone to do your bidding, even though in fact you’re just a rude asshole.
Szarogęsić się is an interesting verb. It comes from szara gęś – a grey goose – and means the same as rządzić się jak szara gęś. So you could say it’s a whole idiom neatly packaged in one word… Something like "greygoosing," even though it sounds horrible in English.

kaczka dziennikarska – a journalistic duck
A misleading newspaper story. In English it’s called a canard, which comes from the French for duck as well.

puszczać kaczki – to let out the ducks
To skip stones on the water.

do białego rana – all night long, until dawn (lit. until the white morning)

very often used with the verb bawić się – to have fun, to enjoy oneself, especially at a party

Po ostatnim egzaminie studenci bawili się do białego rana.

After the last exam, the students had fun until dawn.

w biały dzień – in broad daylight (lit. in the white day)

rozbój w biały dzień – daylight robbery

Morderstwa dokonano w biały dzień.

The murder was commited in broad daylight.

Te ostatnie podwyżki cen to rozbój w biały dzień!

These recent price rises are daylight robbery!

białe szaleństwo – snow fun; winter sports, especially skiing, done for fun (lit. white madness)

Miłośnicy białego szaleństwa są zachwyceni pogodą w Tatrach.

Snow fun fans are delighted with the weather in the Tatra mountains.

biały kruk – a rare book (lit. white raven)

Pierwsze wydanie tego słownika to prawdziwy biały kruk.

The first edition of this dictionary is a real rarity.

białe małżeństwo – a marriage without sexual relationship (lit. white marriage)

Byli niezwykle pobożni, więc zdecydowali się na białe małżeństwo.

They were extremely pious, so they decided on a sexless marriage.

biała plama - a blank spot, an unknown, unexplored area (lit. white spot)

Ten ubogi region to biała plama na turystycznej mapie Polski.

This poor region is a blank spot on the tourist map of Poland.

Trygonometria była białą plamą w wiedzy studenta.

Trigonometry was a blank spot in the student’s knowledge.

widzieć białe myszki – to see pink elefants (lit. to see white mice)

Stefan zaczął widzieć białe myszki. Postanowił przestać pić.

Stefan started seeing pink elefants. He decided to give up drinking.

czarny character – villain, (lit. black character)
Voldemort to czarny charakter w książkach o Harrym Potterze.
Voldemort is the villain in Harry Potter books.

czarno na białym - in black and white, (lit. black on white)
Jest napisane czarno na białym, że nie wysyłamy towaru za granicę.
It’s written in black and white that we don’t ship goods abroad.

czarna robota – unpleasant, tedious work that no one wants to do, (lit. black work)
odwalać czarną robotę – to do the unpleasant work – it’s a very informal verb! You don’t wan’t to use it in a formal context.
Najmłodszy pracownik musiał odwalać za wszystkich czarną robotę.
The youngest employee had to do the unpleasant work for everyone.

na czarno – illegally (lit. in black)
pracować / zatrudniać / zarabiać na czarno – to work / employ / earn illegally, without paying taxes
Młoda ekspedientka  była zatrudniona na czarno.
The young shopping assintant was employed illegally.

czarna owca – black sheep
Bezrobotny i biedny Stefan był czarną owcą w rodzinie.
The unemployed and poor Stefan was a black sheep in the family.

czarny koń - dark horse, (lit. black horse)
Młody, niedoświadczony zawodnik okazał się czarnym koniem wyścigu.
The young, inexperienced competitor turned out to be the dark horse of the race.

czarny rynek – black market
sprzedać / kupić coś na czarnym rynku – to sell / buy something on the black market
Kupiłem ten pistolet na czarnym rynku.
I bought this gun on the black market.

czarna magia – all Greek to me, (lit. black magic)
Komputery to dla mnie czarna magia!
Computers are all Greek to me!

czarna godzina – economic problems, rainy day, (lit. black hour)
trzymać coś na czarną godzinę – to hold something back for a rainy day
Trzymam te pieniądze na czarną godzinę – nigdy nie wiadomo, kiedy się przydadzą!
I’m holding this money for a rainy day – one can’t know when they come to use!