Cheap lenses

[rum pig]

Hi I have been on Ebay and noticed some cheap lenses and I wonder if they are any good. Before you tell me you get what you pay for I don't expect them to be as good as top of the of the range but more a beginners cheap start to see if he likes and uses it enough to cough up the big coin. I understand these are manual focus so no bells and whistles but I'm more worried about clear and sharp pic's that will not be blown up to poster size.
Here is a link to one I was talking about *removed, please read site rule 4 *
Also can someone explain to me how these lenses work in laymen's terms and if they are any good.
*removed, please read site rule 4 *

Thanks in advance for your help