Some tips for beginners :

Choose easiest difficulty. The game is harder than it seems.

You have three main problems :
- Doing the story missions correctly (failing them will usually get you killed)
- Keeping the faction reputation up (anything below 10% will get you killed).
- Getting enough money.

Don't bother getting more rooms than 4-5, you won't need them for a long time. Or at all.
Unlock rooms 103, 105, 106. Together with 102, these are big rooms which can hold a lot of furniture and thus fetch a good price.
Clean and furnish these and upgrade their bathrooms when possible. Also upgrade the hallway in the 2nd floor, it will raise the prices as well.

Spend your money on keeping faction relations up by buying alcohol. Aim to keep them above 50%.

Your aim with the rewards is to get decoration items (like grammophones, sewing machines etc.). Using these will "style" a room in the way a certain action likes it. Then rent out these rooms to members of that faction to avoid the rep loss when giving them a normal room. This is very much based on chance since the rewards are randomized and in most cases will not give decoration items. If you absolutely need them, replay the day (see below) to get a chance for different rewards.

Do not bother with the newspaper events, the rep or money loss isn't worth it. Do not read the newspaper at all or you will have to make a decision.

The Francesca mission has a bug upon completion which drops your rep with the russians to 0 or 1% which will get you killed. To get around it you can try to use Cheatengine to find the rep score (preferrably the day before the mission) and move it up. Or look at the video posted by someone else here under "Guides" who managed to get the rep up to 12% somehow.

If anything goes wrong and you fall below 10% rep with one faction with no alcohol left to buy or you want to replay the day, exit the game immediately. The game autosaves at midnight. If you die, the game deletes your save and forces you to start over.