[Tuglist] Doubts

[mk nas]

Hello Sir, 
I am trying to use LATEX With default setting I know how to type an Article with Mathematical equations and formula. As there is no one in my neighbourhood who is familiar in working with it I am mailing a few of my problems – Please help me.
PROBLEMS
I	 ADJUSTING THE LINE SPACING IN AN ARTICLE	
 Icould not get the output in double/one and half spacing . I have used the \usepackage{setspace} and \doublespacing in the preamble of a document of the article Type. On running LATEX  I am getting the following
		Package : ‘Setspace’ 6.6 <2000/03/03>
		!Text line contains an invalid character.
		1.421… \csname p@footnote\endcsname\@the fnn”^^@,,!^^@......
		?
Please HELP

II	 ADJUSTING THE FONT SIZE OF PRINTED OUTPUT IN AN ARTICLE
	
	 Earlier I was getting printed output in the normal size with 11pt option. Now the printout of the same file I am getting with very large letters, how can this be brought back to the normal size. Please note that the letter size specified in the document class is still 11pt itself.
Please HELP


Thanking you,