#Step 1 - Make sure things are formatted correctly WordPress itself depends on the headers at the top of your main plugin file. In many cases, if your plugin is "My Cool Plugin" this file is my-cool-plugin.php in the main directory of your folder. Make sure the top part of the file follows this format:

#Step 2 - Check out the SVN repository

##Install TortoiseSVN if you don't have it already. TortoiseSVN is an open source Subversion GUI for Windows. Trust me, using the GUI is infinitely easier than trying to do things from the command line. You'll run into fewer problems, too.

##Check out your WordPress-hosted SVN repository Find a place where you want to store the WordPress-hosted version of your plugin. By default, I use /My Documents/WordPress/ for all of my hosted dev work. Right-click inside the folder, and select "SVN Checkout" from the dropdown menu.

##Copy your latest version into /tags This is where I do things backwards from most tutorials. Everyone else will tell you to commit /trunk first, but remember that WordPress doesn't use anything in /trunk except the readme file when looking at plugins. So if you put your plugin into /trunk and lose your network connection (or something else goes wrong) before you commit a tag, you'll have issues.

##Copy your latest version into /trunk Now navigate to the /trunk folder of the repository and once again copy-paste your plugin to that folder. Go through the same steps above to select your files and prepare the commit. But for a message, use something that explains what the new release does:

##Updating a plugin to a new version Once your plugin is in the wild, preparing an update is relatively easy.

Step 1 - Make sure things are formatted correctly

WordPress itself depends on the headers at the top of your main plugin file. In many cases, if your plugin is "My Cool Plugin" this file is my-cool-plugin.php in the main directory of your folder. Make sure the top part of the file follows this format:

Step 2 - Check out the SVN repository

Install TortoiseSVN if you don't have it already.

TortoiseSVN is an open source Subversion GUI for Windows. Trust me, using the GUI is infinitely easier than trying to do things from the command line. You'll run into fewer problems, too.

Check out your WordPress-hosted SVN repository

Find a place where you want to store the WordPress-hosted version of your plugin. By default, I use /My Documents/WordPress/ for all of my hosted dev work. Right-click inside the folder, and select "SVN Checkout" from the dropdown menu.

Copy your latest version into /tags

This is where I do things backwards from most tutorials. Everyone else will tell you to commit /trunk first, but remember that WordPress doesn't use anything in /trunk except the readme file when looking at plugins. So if you put your plugin into /trunk and lose your network connection (or something else goes wrong) before you commit a tag, you'll have issues.

Copy your latest version into /trunk

Now navigate to the /trunk folder of the repository and once again copy-paste your plugin to that folder. Go through the same steps above to select your files and prepare the commit. But for a message, use something that explains what the new release does:

Updating a plugin to a new version

Once your plugin is in the wild, preparing an update is relatively easy.

=== [Plugin Name] ===
Contributors: [Your WordPress.org username]
Donate link: [A site people can go to to give you money]
Tags: [Search terms related to your plugin]
Requires at least: [Minimum version of WordPress required]
Tested up to: [Newest version of WordPress you've tested with]
Stable tag: [This version number]

[Short, one-sentence description of your plugin]

== Description ==

[Long description of your plugin]

== Installation ==

[Steps required to install the plugin]

== Frequently Asked Questions ==

= [A question] =

[An answer]

= [Another question] =

[Another answer]

== Screenshots ==

== Changelog ==

== Upgrade Notice ==

=== [Plugin Name] ===
Contributors: [Your WordPress.org username]
Donate link: [A site people can go to to give you money]
Tags: [Search terms related to your plugin]
Requires at least: [Minimum version of WordPress required]
Tested up to: [Newest version of WordPress you've tested with]
Stable tag: [This version number]

[Short, one-sentence description of your plugin]

== Description ==

[Long description of your plugin]

== Installation ==

[Steps required to install the plugin]

== Frequently Asked Questions ==

= [A question] =

[An answer]

= [Another question] =

[Another answer]

== Screenshots ==

== Changelog ==

== Upgrade Notice ==

These instructions assume you're using a Windows computer.

These instructions assume you're using a Windows computer. If you're on a Mac, you can use SCPlugin instead of TortoiseSVN. The steps you'll need to follow will be the same, only the contextual menus and screenshots will differ slightly because of the UI. I don't have a Mac, so I can't create screenshots to walk you through a tutorial ... but trust me, it's the same process.