There are many extensive and detailed good answers already, but i think they are missing something i consider essential and decided to share (note i assume your robots are not sentient):
even if you don't like to read walls of text, at the very least you must check out the reference video "Humans Need Not Apply", by CGP Grey.
The thing that robots excel at, will excel at, and have always excelled at is brute force. You may not conciesly realise it but even today there are tens of thousands, if not more, robots that do manual labor, they build cars, ships, you name it, of course you know about that but what i am suggesting by "you may not conciesly realise it" is that as little as a couple of decades ago only human hands built cars, now almost no humans build cars (throughout my entire post i shall not consider single luxuries like the Bentley, for they are quite literally a luxury, they are neither more powerful, nor more durable, nor considerately superior to other cars in any other way but in price) once sophisticated enough sensors and motors are designed robots will IMMEDIATELY take the jobs of (can't think of the english word for this, sorry) any people who have to lug heavy objects a distance, like delivery of heavy stuff, moving furniture from one home to another, etc.
Actually robots are INCREDIBULY well suited for repeating tasks, be they complex or not. For example "baristas", or in other words the people that get paid to hand you coffee, can be easily replaced by a robot. That is not something that "will be done" - it is done, now. There already is a robot that makes you coffee when you click the necessary buttons on him (makes you wonder why it took people so long, eh) even better yet if you log your phone, it can detect you and your preferences when you are near him and make you the exact same coffee that you love. I am sorry but i don't have the relevant story/article on this, but i am sure you can google it :P
You can pretty much replace more than 60% of existing jobs with robots even today. Grocery store? Why pay substantial money to someone who just waves his hand over a scanner, considering there are self-checkouts how hard would it be for a bot to do? Or better yet - replace the bar code with and RFID tag, this will basically allow stores to get rid of cashiers as a sensor near the gate will automatically detect what products you are carrying and can even automatically tax your willingly provided account.
Other jobs that robots can take over very, very soon are: lumberjacking, fishing, mail delivery, driving, art, music, layering and etc.
Now, some of these may confuse you, allow me to explain...
You may not know but being a lawyer in the US is a lot less convincing a judge your client is innocent and a lot more reading e-mails. The majority of lawyers in the US are hired by big corporations to look/hunt for inaccuracies in fiscal documents. This means they shift through hundreds of emails each day making sure each decimal is in place and corresponding to a decimal in another email or piece of paper or whatever. Well, guess whose purpose ever was to do the same thing over and over again?
Driving is something else not everyone has realised robots can do. Today. This is not something that will happen, it's already happening, there were plans for cars that could drive themselves twenty or more years ago, today they are a reality, them becoming popular is just a matter of a few years.
Art and music is where most people would not agree with me. Well, that's though, because there already is music and paintings being produced by robots, and not bad ones. Here is where i make my second important point (the first one being robots are here today and not in the future) you don't need robots to be better than humans the way any industry works is it produces something at a given level reliably. Mercedies does not make the best cars anyone has ever seen, or the fastest, or the safest - it makes good cars. Baristas all over the world do not make the best coffee anyone has ever tasted, they make good coffee, professional musicians (not world-famous rock stars, mind you) do not play new masterpieces every day. Noone needs their employees to produce the best they can do, everyone needs a medium quality product over and over again. No driving company cares if Michael Shumaher drives one of their trucks, they just don't want a blind person driving one of their trucks. Robots may never create the next "Bohemian Rhapsody", or the next "Mona Lisa", but they don't have to. They just have to be just as, or a little worse than us. There is no way you could recognise a record of Beethoven's 9th over a live performance, if the performer was not visible, and even that is not important, like i said there already is music being made by robots with no external input beyond the programming. It is not the greatest music you ever heard, but it is a pretty nice tune. Considering modern art, where a chimp's painting can be sold for hundreds of thousands of dollars, can you really argue robots can't do that? (and in case anyone wonders, yes, there really was a case where researchers gave a chimp some paint and a canvas, the result was that one art critic valued that paining to be the best of an entire exhibition. He was later informed of the artist's roots and the critic still said that was the best painting) Like i said - probably no Mona Lisa, but people don't buy Mona Lisas every day.
I have even heard of a robot writing a very short story that made sense. On that i have no further information, though.
The question is - what happens when suddenly or even over the course of a few years hundreds of thousands of people end up unemployed? You would have to ask someone who understands how societies and governments work. Because another major point you have to consider is - what does a government do when it realises its people can't pay taxes? Everything can't be free. Why? Well, because someone owns the robots. And sure as hell it ain't going to be the government. Major problems include:
1. People are not equal. As long as there is something people can do that robots can't someone will want it and in order to provide it someone else will want to be payed "something".
2. It is going to get really complicated when you realise modern governments rely on people supplying them with both menial and specialist labor AND paying taxes - what do you do when you have a, figuratively, endless supply of labor that does not care how good you politicianing is and organics that can't pay taxes? Protip: the answer "you make taxes free" is completely unacceptable. (another completely unacceptable answer is "get rid of the organics)
For more detailed overview on most of the things i said, check out this awesome video by CGP Grey on YouTube.