Weed control strategies
In most no-till systems, a mixture of a burndown herbicide plus one or more residual herbicides is normally used for weed control.
The burndown kills existing vegetation before or after planting. Residuals are normally applied before or after planting to control weeds germinating from seed. To complete the weed control system, one or more postemergence herbicides may be needed later for broadleaf weeds or grasses or both.
We mention this general scenario to give you an idea of the products involved, not to outline any sort of normally-followed-pattern. Certain "routines" can cost a lot more money than you need to spend. Any weed control program should be based on sound scouting, not overkill.
For instance, it is not unusual for some no-till soybean growers in the Midwest to use only a burndown herbicide-no residual or postemergence herbicide at all. Their success is due to fields with a history of low weed pressure, timely and frequent scouting, and narrow row systems. Narrow-rows allow the crop canopy to close early and shade out emerging weeds.
You also can't afford to ignore other traditional weed management tools such as crop rotations, crop competition, and row crop cultivation.

Narrow-row crop production provides faster shading than wide rows. Plant canopies in narrow-rows block sunlight from emerging weeds, limiting weed pressures.

Crop rotations
Certain weeds are easier or more economical to control in one crop than in another. For example, perennial grasses that are difficult to control in corn can be managed effectively in broadleaf crops such as cotton and soybeans. This makes crop rotation important for fighting weeds.

Crop or cover crop competition
A competitive crop that can achieve early shading of weeds can greatly improve weed control. One example is double-crop soybeans (soybeans after wheat in one season). When planted in narrow rows (15 inches or less), double-crop soybeans provide a quick-closing crop canopy that shades emerging weeds. The success of this system depends on good stand establishment since skips allow weeds to escape.
Cover crops can accomplish the same goal. In fact, they are the main reason weed control in small grain production is usually successful. Vigorous stands of cover crops help suppress weed populations by reducing the amount of sunlight that reaches emerging seedlings. Cover crops may also exude natural chemicals that stunt or kill early weed growth among plant types related to the cover. This is known as allelopathy.

Row crop cultivation
Even the best managers have weed control problems from time to time. While the focus of successful crop production is to eliminate tillage and manage crop residue, use of row crop cultivators is sometimes justified.
High-residue or no-till cultivators can be used in a postemergence situation to help control weeds, especially when herbicide control was unsuccessful or too late to consider.
While the no-till philosophy is to keep tillage to a minimum, no one should be expected to put up with serious reductions in yield and income due to weed infestations for the sake of a philosophy. In emergency situations, use row cap cultivation to assist in weed control, but not the moldboard plow or other primary tillage tools unless absolutely unavoidable. As mentioned, significant benefits are gained from continuous no-till systems that exclude all tillage operations.

Note:
The more you utilize row crop cultivation, the higher risk you run of destroying macropores and organic matter content while promoting erosion. Consider carefully the pluses and minuses of such a decision in no-till.