I connected my MacBook 2010 model via Mini Display Port to DVI then DVI to HDMI cable into my Samsung monitor. Then enabled mirror mode where no resoultion fits the screen and is blurry. Is my method of connectivity causing this?
Is that monitor a computer display or a TV? Do you know the exact model? It is often stated on the back. Does the monitor not have a DVI input and if so, why don't you use it?
Definitely use a DVI cable then. If you want to use it in clamshell mode, uncheck mirroring, and mouse over to the other display, which I believe is off of the right side of the screen by default. There you will find that display's resolutions, and simply select the highest one (likely 1920x1080)