A desktop publishing application from Microsoft that focuses on page layout and graphic design.
I don't think they look that bad for the most part, but I noticed some jaggies especially the M in the 4th picture.
'from inspiration to installation' is both a non web friendly font and is in italics. That only increases the chance of getting the jaggies. If you must use that font then at least don't use italics. It can be hard to reproduce 'print formatting' as 'web formatting'. Sometimes there is no HTML equivalent. Try the text without the italics.
I downloaded your pictures and notice that you have an assortment of sizes and formats. Your first picture is a .jpg and is 1250 X 625 pixels, 150 ppi resolution and 132 KB file size. Meanwhile the 4th picture is a .png at 1875 X 937 pixels, 150 ppi, and has a huge 1.29 MB file size...and it shows the most problems. You need more consistency.
First of all when you set up your picture in Publisher don't make the pictures any wider than necessary. Make them the same width as the maximum for the web page. I don't know if you are working in pixels or inches but if you are producing a 8.5 inch wide page then the pixel width would be .96 X 8.5 or about 816 pixels wide. Also save the pictures at 96 ppi for the web. This reduces the file size and will speed up the loading time. If someone with a dial-up web connection viewed your site that 1.29 MG picture could take 5 minutes per MB to load. 150 dpi is for print, not web pages.
Your choice of a png is usually going to be your best choice for minimizing the jaggies.
Try producing the pictures at the correct size, 96 ppi, as png files, no italics and possibly a web friendly font and see if that helps.
Alternatively use a third party image editor to create your images. Publisher makes it easy but has limitations as an image editor.
DavidF