Manors & Dominions

I'll use the lowest listed 1e PHB rate of 5 sp/month as a default, with a Fighter of level 5-8 as ruler or steward, or a level 8 Cleric Patriarch, able to raise 6sp/month, about the OD&D level at 10 sp per gp.  Other rates as below.

1e AD&D uses monthly rates:
Fighter Dominion 7 sp/month Presumed default. This seems an appropriate rate for Paladins also, and possibly Rangers, if Aragorn is an example.
Clerical Dominion 9 sp/month Presumably includes tithes, so we can see that the Church may claim up to 2sp/month/person above the default rate.
Magic-User Dominion 5 sp/month Magic-Users apparently make poor rulers, having "many other demands on their time". This seems an appropriate income rate for other classes without specific rulership skill, such as Druids, Thieves & Assassins.
A kindly GM may allow the weaker rulership classes to employ a Steward, typically a Fighter type of level 5-8, who can raise taxes at the default rate of 6 sp/month, or 7 sp/month if the Steward is a Fighter type of level 9+. 9 sp/month should be reserved for theocratic dominons.
Note that subsistence income and minimal average GDP per person, including the non-productive, is 1 sp/day, or 30 sp/month. A typical 5 person household produces GDP of 150 sp/month.

New Manors
Initially attract freeholders on a manor equal to 'Max Henchmen' score x10 and if there's plenty of land grow as per table below. Of course diplomacy and conquest can enable rapid growth...
For random potential areas optionally roll 3d4 for the likely gp/year reflecting resources; Fighter Lords add +2 to the roll. 10gp/year assumes a near optimum environment.

Lord's CHA: Initial Freeholders (Manor)
3-4:  10; Growth -3%
5-6: 20; Growth -2%
7-8: 30; Growth -1%
9-11: 40; Growth +0%
12-13: 50; Growth +0%
14: 60; Growth +0.5%
15: 70; Growth +1.5%
16: 80; Growth +2%
17: 100; Growth +3%
18: 150; Growth +4%
19: 200; Growth +5%
A typical manor in settled farmlands is 640 acres, or 1 square mile. Maximum manor size in borderlands is roughly 2 miles diameter (one 2 mile hex), or just over 3 square miles, of which no more than 1 square mile is likely farmland. Exceptions apply to rulers of exceptional charisma - see below. Otherwise new manors must be created to administer the growing population.

Manor Current Population & Base Growth Rate (annual)
Under 20       +30%
20                 +25%
40                 +20%
60                 +15%
80                 +10%
100                 +5%
125                 +4%
150                 +3%
200                 +2%
300                 +1% requires 1.5 square miles farmland
400                 +0% " 2 sq m"
500                  -1% " 2.5 sq m"
600                  -2% " 3 sq m"
700                  -3% " 3.5 sq m"
800                  -4% " 4 sq m"
900+                -5% " 4.5 sq m"

A sub-infeudinated manor must have a lord or thane, preferably a henchman/retainer of the higher lord.

Resource Investment
For every 200gp spent on resource development in a month, a manor will attract 1d10 more people. Growth limits still apply.

Typical Domain Costs
A typical domain has gross income of 10gp/person/year and expenses of 75% of income, leaving a net income of 2.5gp/person/year.
Garrison: 20% (civilised)-30% (borderland)-40% (wilderness) of income (2gp-4gp/person/year)
Stronghold Upkeep: 5% of stronghold cost per year; typical strongholds cost = annual domain income x2 (civilised) x3 (borderland)  x4 (wilderness), so typically 10%-20% of income, 1-2gp/person/year
Salt Tax: 20% of gross income to higher lord, 2gp/person/year
Tithes: 0% (wilderness) -5% (borderland)-10% (civilised) of gross income to local churches/temples, 0gp-1gp/person/year
Festivals & Alms: 5% of income, 0.5gp/person/year

Urban Investment
It takes 1 year to create a new settlement at a suitable locale. Once created, the settlement maximum population figure is added to the maximum population figures above, so eg +30% annual growth requires a population fewer than 20 above the numbers below.
Investment  Additional Maximum Population
 10,000gp      +1000 Small Town
 25,000gp      +3000 Town
 75,000gp      +10000 Small City
200,000gp     +25000 Large City
625,000gp     +100000 Metropolis
2,500,000gp  +500000 Grand Metropolis

Growing a Manor (D&D & Mini Six)

The following rules are for D&D based systems. For Mini Six, replace Charisma with Charm - either rolled or taking 3 per Die for passive, so eg Charm 3d6+2 is a passive score of 11.

MANORS & DOMINIONS
OSRIC says high level Fighter Lords can extract 1gp/month per resident in a freehold; for general play I'm going with 10gp/year gross income for a typical borderland manor, which is the OD&D level. Initially attract I reckon freeholders on a manor equal to 'Max Henchmen' score x10 and if there's plenty of land grow quickly to around 100, slower thereafter. Of course diplomacy and conquest can enable rapid growth...

Lord's CHA: Initial Freeholders (Manor)
3-4:  10; Growth -3%
5-6: 20; Growth -2%
7-8: 30; Growth -1%
9-11: 40; Growth +0%
12-13: 50; Growth +0%
14: 60; Growth +0.5%
15: 70; Growth +1.5%
16: 80; Growth +2%
17: 100; Growth +3%
18: 150; Growth +4%
19+: 200; Growth +5%
A typical manor in settled farmlands is 640 acres, or 1 square mile. Maximum manor size in borderlands is roughly 2 miles diameter (one 2 mile hex), or just over 3 square miles, of which no more than 1 square mile is likely farmland.

Manor Current Population & Base Growth Rate (annual)
Under 20       +30%
20                  +25%
40                 +20%
60                 +15%
80                 +10%
100                 +5%
125                 +4%
150                 +3%
200                 +2%
300                 +1%
400                 +0%
500                  -1%
600                  -2%
700                  -3%
800                  -4%
900+                -5%