Well done Sean. If you want to re-size photos (which is needed, as they're slowing things down!), then use 'Irfanview'. It's free to download, and very easy to use.
Just go to the 'Re-size/Re-sample' line and click. A box will appear, showing the current size (in pixels), with the option for cms or inches below. Uner 'Image', click on the 'Fit to screen' and 'OK' and the image will now show fully, fitted to screen size. This can then be cropped if required, by left clicking and 'drawing' a box around the area you want, which can be enlarged and reduced vertically and horizontally as required. When happy, click on the 'Crop' line under the 'Edit' heading, then use the 'Re-size' to set the required size. You only need to enter one dimension, with the maximum for the forum being 800 x 600 pixels. So, for example, enter '800' and click 'OK' and it'll automatically size accordingly, retaining proportion. Then, click 'Save As', and give it a name or title, which will retain the original image uncropped or re-sized, but give the new image as a separate image title/file.
You can also use the programme to adjust colour balance, tone and contrast, and 'Gamma Correction' will improve a dark shot whilst retaining tonal balance and contrast, as well as a number of other very useful features you'll eventually discover.
Hope this helps.