How do I combine PDFS

I am helping a professor with articles from newspapers.com. She would like me to combine articles that are not on the same page into one PDF. Also, is there a way to select the entire text transcription and copy/paste into a text file, and send that to her too? She wants to make an html version of the article and provide a pdf of the real thing for download. 

I realize these are elementary questions, but I don’t work often with Acrobat and could really use some help. Thank you!