When you place a building in the game, it will not be functional until the employer "walker" passes by a house. The secret here is that as soon as the employer finds a single house, the building instantly has access to every single worker in the entire city, to every house in the game. So you don't need to build direct access to your main housing district. You can place a cheap hut somewhere near the industry district, and your industry will have workers from all over the city map. While your main residential district can be focused on beautiful gardens and optimal service access.

When you lay down the roads, think in loops and avoid intersections.
The walkers are going to mess up if you put too many intersections because they will randomly choose paths that aren't good. Use roadblocks as soon as you unlock them in the campaign in order to isolate loops. Then use connecting roads between the loops for walkers with destinations.

Walkers with destinations: Delivery guys, Bazaar gatherers, Entertainment walkers travelling to a bandstand or juggling booth.
Service walkers: Firemen, Water carrying dudes, Bazaar distributers, Priests, Scholars, Taxmen.

The walkers with a destination will be able to go through the roadblocks and gather resources or deliver goods, and regular service walkers will stick to the loops you designed and not cross the roadblocks. In the first levels where there's no roadblocks, you'll have to persevere and try your best with the sub-optimal roads, but don't worry: The roadblocks unlock quickly in the 4th map or so.

It might be tempting to start placing everything as soon as you start designing the city. However, as soon as you place a building it will start deteriorating and getting ready to catch on fire and create a disaster.
So, first of all try to have your firemen (engineers and so on) "walkers" ready to go, before placing the big buildings.

The requirements for house upgrades increase a lot in each difficulty setting. If you find it impossible to upgrade houses even when you think you're providing them with the goods and services required, try lowering the difficulty and see if that solves the problem.

This is a bit more on the intermediate/advanced planning.
When you right click an industry building or bazaar, In the properties menu, you will find settings such as "Get Maximum" "Accept All" "Do not accept". These settings will help you plan a flow of goods.

Setting bazaars that only purchase specific goods, in that way their Gathering walkers will travel only to the industry location that you want. Pottery or beer bazaars will go to the specific storage yard and return with the goods. While food bazaars will only travel to the granaries and bring specific foods. This will make them restock better instead of having to split and do multiple travels in order to stock every single product in your city.

I will be adding more tips and ideas as I learn them and figure the game out more. Maybe add some screenshots and graphics to spice things up a bit.
I hope this guide is useful and/or interesting. Enjoy the game!