The first step in participating in an election is to register to vote. Doing so is a simple process which only takes a few minutes. Below is a list of links with the requirements and process to become a registered voter for each state.
http://www.sos.state.al.us/elections/voterregistrationinfo.aspx
http://www.elections.alaska.gov/vi_vr_how.php
http://www.azsos.gov/election/voterregistration.htm
http://www.sos.arkansas.gov/elections/Pages/voterRegistration.aspx
http://www.sos.ca.gov/elections/elections_vr.htm
https://www.sos.state.co.us/Voter/secuRegVoterIntro.do
http://www.ct.gov/sots/cwp/view.asp?a=3179&q=489908
http://electionsncc.delaware.gov/votreg.shtml
http://election.dos.state.fl.us/voter-registration/voter-reg.shtml/
http://sos.georgia.gov/elections/vrinfo.htm
http://hawaii.gov/elections/voters/registration.htm/
http://www.idahovotes.gov/vinfo.htm
http://www.elections.il.gov/votinginformation/register.aspx
http://www.in.gov/sos/elections/2403.htm
http://sos.iowa.gov/elections/voterinformation/voterregistration.html
http://www.kssos.org/elections/elections_registration.html
http://elect.ky.gov/registertovote/Pages/default.aspx
http://www.sos.la.gov/tabid/457/default.aspx
http://maine.gov/sos/cec/elec/votreg.htm
http://www.elections.state.md.us/voter_registration/index.html
http://www.sec.state.ma.us/ele/eleifv/howreg.htm
http://www.michigan.gov/sos/0,1607,7-127-1633_8716_8726_47669---,00.html
http://www.sos.state.mn.us/index.aspx?page=204
http://www.sos.ms.gov/elections_voter_info_center.aspx
http://www.sos.mo.gov/elections/s_default.asp?id=voter
http://sos.mt.gov/elections/Vote/index.asp
http://www.sos.ne.gov/elec/voter_info.html
http://nvsos.gov/index.aspx?page=703
TBD
http://www.state.nj.us/state/elections/voting-information.html
TBD
http://www.elections.ny.gov/VotingRegister.html
http://www.ncsbe.gov/content.aspx?id=1&s=1
http://www.nd.gov/sos/electvote/voting/voter-qualifi.html *
http://www.sos.state.oh.us/elections/Voters/register.aspx
http://www.ok.gov/elections/Voter_Registration/
http://oregonvotes.org/pages/voterresources/regtovote/index.html
http://www.votespa.com/portal/server.pt/community/register_to_vote/13518/
http://sos.ri.gov/elections/voters/register/
http://www.scvotes.org/south_carolina_voter_registration_information
http://sdsos.gov/content/viewcontent.aspx?cat=elections&pg=/elections/registrationvoting.shtm
http://www.tn.gov/sos/election/registration.htm
http://www.sos.state.tx.us/elections/voter/reqvr.shtml
http://vote.utah.gov/register-to-vote/
http://vermont-elections.org/elections1/registertovote.html
http://www.sbe.virginia.gov/cms/voter_Information/Registering_to_Vote/Index.html
https://wei.sos.wa.gov/agency/osos/en/voterinformation/Pages/RegistertoVote.aspx
http://www.dcboee.org/voter_info/
http://www.sos.wv.gov/elections/voterinformation/Pages/Voter_Registration.aspx
http://gab.wi.gov/elections-voting/voters/registration-voting/
http://soswy.state.wy.us/Elections/RegisteringToVote.aspx
http://www.eac.gov/voter_resources/register_to_vote.aspx
* While North Dakota does not require individuals to register to vote, this page outlines the voter qualifications for North Dakota.