add stamp, text, highlight on a existing pdf

I making a aplication in VB.net, to view, edit and merge 2 Pdf.

By adding the Adobe PDF reader COM Component in my toolbox i can view my pdf, but i dont, have the capabilité to add text, stamp,  highlight are not availible.

What is the best way to add stamp, text, , check, arrow, highlight on existing PDF?

Thank's for your help, and excuse my english, i'am a french guy

daniel