\documentclass[11pt,a4paper]{article}

\usepackage{marginalia}
\marginaliasetup{
  ysep page top=0mm,
  style recto outer=\raggedright\footnotesize,
  style recto inner=\raggedleft\footnotesize,
  width=30mm,
}

\begin{document}

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod%
\marginalia[valign=t]{{\large\ttfamily valign=t}\\The baseline of this marginal note
  is the baseline of the its top line.}%
\marginalia[valign=b,pos=reverse]{{\large\ttfamily valign=b}\\The  baseline of this
  marginal note is the baseline of its bottom line.}

\vspace{30mm}

Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris
nisi%
\marginalia[valign=c,pos=reverse]{{\large\ttfamily valign=c}\\The baseline of this
  marginal note is midway between the top and bottom of its content.}%
\marginalia[valign=m]{{\large\ttfamily valign=m}\\The baseline of this marginal note
  is midway between the baseline of its top line and the baseline of its bottom line.}

\end{document}

