Step 1 - Find Your Host
If you have not already done so, then you need to decide on where you will be hosting your website. Look about for a site host that offers the services that you need at a price you are happy to pay. To install WordPress, you will need basic hosting along with a MySQL database, so look at the price of that. If you are creating in excess of 1 blog then maybe look at accounts that will host multiple sites, even reseller accounts.
If you are lucky you might select a host that has one click WordPress installation. If so, then do the next step and the one click installation and forget the rest of the steps!
Step 2 - Buy Your Domain Name
As a rule this is part of setting up your hosting. Think of a good domain name, check if it is available (your likely hosts will have a tool for this) and go for it! Do not be tempted to stuff the domain name with keywords. Keep it short and snappy and good looking. If keywords fit into it, then fine. But a name that describes the weblog or is based round your name could attract more visitors long term.
Step 3 - Install A Database
This may be automatic with some hosting packages and with others you need to click a button to install the database and set-up an admin user id and password. Make a note of the access details your host gives to you.
Step 4 - Download WordPress
Go to WordPress.org, click download and get a copy of the lastest version. Save it to your computer then using Windows Explorer search for the folder that you have downloaded to. It arrives as a zip file, which you straightforward unzip by opening the zip file in Explorer then dragging the WordPress folder into an alternative folder. It will take a minute or two to unpack.
Step 5 - Customise the Installation
Look at the readme file in the unpacked folder, but basically you take a copy of the wp_config file and edit it with the user id, password and perhaps database location from step 3.
Step 6 - Upload WordPress
Now the hard part, if you are not used to it! If you have an FTP package then just use that to upload the unzipped contents of the WordPress folder to your website (the contents just).
If you do not have FTP software, the you could use Internet Explorer to do the trick. Type into the address bar the address your hosts have given you for FTPing, sign on and then navigate to the folder on the site you need to upload to. (Certain versions of Internet Explorer require you to confirm you want to use FTP by going for an option under the tools menu on the top right.) Now, just drag the contents of the unzipped folder to the folder on the web site.
Step 7 - Install
Type in your website address and follow the instructions on the screen, you are seconds away from having a new website! Choose a password and (onWordPress 3.0 onwards) select a user id and you are running.
Now, you only need to start customising WordPress and change some security settings. Easy when you know how.