Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
Thompson and Moncrief, eds. 1998. Campaign finance in state legislative elections. Washington DC: CQ Press.
Lays out the general approach of the book. Looks at how campaign spending/finance varies with (1) legislative professionalism, (2) size of the state, (3) campaign finance laws, etc. See Table 1-2 (pg 15).
Many of the conclusions are what you would expect: e.g. Candidates spend more money in contested primaries than uncontested. A significant conclusion is that the incumbency advantage kicks in early in the campaign, with incumbents raising significant sums during primaries--and spending it in the general election (against a challenger who probably had to spend more just to win his primary). Thus, campaign finance reforms that put limits on contributions might have an effect opposite to what is intended: They might put a further handicap on challengers (relative to incumbents).
The controversy (chicken-egg): Does money cause election results, or does money simply go toward likely winners?
Research by the same authors
Research on similar subjects