Regex Confusion

[Kelly22]

I have been working on a a perl script for awhile and everything is going well other then I am constantly confused by how the regexs work.

It is my understanding that a line like string =~ s/"//; should replace all occurrences of " with nothing. However the strings it acts on usually have 2 ", and to eliminate both of them I have resorted to repeating the line.

Another series of regexs are not working as I expect them to either.

foreach (@content) {
    if ($content[$count] =~ /entertainment_headlines.gif/ or $content[
+$count] =~ /Chewy Headline Snacks/
        or $content[$count] =~ /FEATURED INK/ or $content[$count] =~ /
+StatCounter/ or  $content[$count] =~ /NW Insider/
        or  $content[$count] =~  /twitterbadge22/){
        splice(@content, $count, 1);
    }
    $count++;
}

I believe this should elimiate array entries that contain these strings, but it doent seem two work msot of the time. It doesnt eliminate the array entry that ends with

 </table>
            </div>
                <div class="moduletable">
                            <h3>
                    FEATURED INK                </h3>
                <table class="contentpaneopen">

or the one that contains

<!-- Start of StatCounter Code -->
<br /><script type="text/javascript">
var sc_project=3028426; 
var sc_invisible=0; 
var sc_partition=32; 
var sc_security="0f2a9250"; 
</script>

<script type="text/javascript" src="http://www.statcounter.com/counter
+/counter_xhtml.js"></script><noscript><div class="statcounter"><a cla
+ss="statcounter" href="http://www.statcounter.com/"><img class="statc
+ounter" src="http://c33.statcounter.com/3028426/0/0f2a9250/0/" alt="f
+ree html hit counter" /></a></div></noscript>
<br /><!-- End of StatCounter Code -->

And while I am at it I also want to elimiate all newline characters from a string and assumed that $string =~ s/\n//; would do that but it doesnt seem to work at all.

Clearly I am not getting something about regexs. I have read up on them and its still not clear to me what I'm doing wrong. Any help or generally some negative reinforcement would be greatly appreciated.