beginners of .net programming can't guess sometime that
how easy is sending mail through .net.there are many ways
to do that.but i am writing here the easiest method to send
mail in c# with .net.It doesn't involve a lot's of coding.
all is built in and no more components.

following are guidelines to develop modules
for dotnetnuke 5/6 with visual studio 2008/2010 -

It's a great idea to show application related tips
when users run your application.you may show tips
about how to use your application efficiently,details
of your application terms,etc.

Asp.net caching helps you to create high performance applications.
you can cache objects like DataSets,or your created objects.you can
also do page level caching if you used user controls in the page
if your aspx page includes lots of work.

to display the help and let the users easily get help
whenever they need it you can call the Help.ShowHelp
method in your form.