Creating a PDF file in vb.net

I am trying to write a vb.net program that will create posters dynamically.  I would like to print the posters on 11x17 posterboard.  I was told the best way to do this is to create a pdf file and then just send that to a printer.  My question is what do I use to create a pdf file?  My program would need to take 8 images and place them in a set postion on the 11x17.  4 on the front and 4 on the back.  I also need to add a caption under each image.  So my program would select 8 rows from my database.  Each row would have the image directory and the caption, I would then have to put them in the pdf and save the file for print.  I can do the database stuff but I do not know what tools to use to create the image.  Does anyone know how the best way to create the pdf?  Do I need to create a "pdf template" and just place my images on some kind of tag?   sample code would help if possible.