Animal Crossing: Wild World - Town Map Generator

1. Pick out the acres that match your town. Underneath each acre is its identifying code.
It might be easiest to start with the acres that contain the main features of your town. That is, the waterfall, gate and the main buildings (Nook & Ables, Museum, Town Hall and your house).
The coast and the river (especially the location of the large pond within the river) are other features that can be used to select acres.
In selecting any acre, the location of the rocks, the holding ponds (the little separate ponds) and villagers houses (this includes the vacant plots, indicated by signs) are a great help.
You will need to have your game open while you select the acres, so that you can view your town and the acres in the table at the same time.

This table show all the different acres that are possible in the game.

14-M1	15-M1	16-M1	17-M1	18-M1	19-M1
1A-M1	1B-M1	1C-M1	Gate
1D-M1	1E-M1	1F-M1	Your House	20-M1	21-M1	22-M1	Museum
23-M1	24-M1	25-M1	Nook / Ables	26-M1	27-M1	28-M1	Town Hall
29-M1	2A-M1	2B-M1	2C-M1
2D-M1	2E-M1	2F-M1	30-M1	31-M1	32-M1	33-M1	34-M1
35-M1	36-M1	37-M1	38-M1	39-M1	3A-M1	3B-M1	3C-M1
3D-M1	3E-M1	3F-M1	40-M1	41-M1	42-M1	43-M1	44-M1
46-M1	47-M1	48-M1	49-M1	Waterfall
4A-M1	4B-M1	4C-M1	4D-M1	4E-M1	4F-M1	50-M1	51-M1
52-M1	53-M1	54-M1	55-M1	56-M1	57-M1	58-M1	59-M1
5A-M1	5B-M1	5C-M1	5D-M1	5E-M1	5F-M1	60-M1	61-M1
62-M1	63-M1	64-M1	65-M1	66-M1	67-M1	68-M1	69-M1
6A-M1	6B-M1	6C-M1	6D-M1	6E-M1	6F-M1	70-M1	71-M1
72-M1	73-M1	74-M1	75-M1	76-M1	77-M1	78-M1	79-M1
7A-M1	7B-M1	7C-M1	7D-M1	7E-M1	7F-M1	80-M1	81-M1
EWNa-M1	EWNb-M1	EWS_C-M1	EWSa-M1	EWSb-M1	EWSd-M1
NSEa-M1	NSEb-M1	WNSa-M1	WNSb-M1
00-M1	Blank Acre (not part of the game)

With Trees/Flowers

2. As you find an acre that matches your town, enter its code in the table on the left. The table is set up the same as your town - a square of 4 by 4 boxes that matches the 4 by 4 acres of your town. (16 boxes/acres in total).
Scroll down within each box, find the code for your acre, select it, and it will show in the table. You can enter one code at a time, several or all of them.

3. When ready to see your town map, or a partial version without all the acres entered, press Preview. This updates your town map, replacing the blank (empty) acres with the acres you have chosen. If you do not see the updated town map, use refresh in your browser (see FAQ below for more detail).

4. When you are happy with your town map, save using right click and select the appropriate action (in Firefox: Save image as.., in IE: Save picture as..). When the browser prompts you to save the image, rename the file to your town name, then save.

FAQ
Why don't I see my map when I press Preview?
The reason for this is technical. For speed, browsers save texts and images on your computer, so that the next time you go to the page the browser does not have to request them again from the web server. The problem with the town map is that some browsers (IE in particular) does not detect that the town map has been updated, so does not request the new version from the web server. Thus it displays the old one, forcing you to manually refresh the page in your browser to get and display the new version of the map.

Alternatively you may go in the browsers settings and change how they handle pages update. For IE under the 'Tools' menu, you select 'Internet Options...' then in the section 'Temporary internet files' press the button 'Settings'. On the top you will see 'Check for newer versions of stored pages:'. To force IE to check for newer versions of texts/images all the time you need to select 'Every visit of the page'.

Special thanks to Katysu for all the help with testing, texts and suggestions.