The date is set, the manifestos are published, and 'none of the above' seems to be the preference for most of the country. Nevertheless, voting is still an incredible privilege and so you really should do it.
Something that may encourage you, or do the complete opposite, is voterpower.org.uk which calculates the importance of your vote according to how likely your constituency is to change hands. (Thanks to Phil Whittall for the heads-up.) Having just moved to the "very marginal" Edinburgh South, my vote is now worth four times the national average, so I really ought to get myself registered.
If, like me, you're not registered yet, go to aboutmyvote.co.uk - and do it soon because the deadline is 20th April.
I don't really have political colours, more principles that I try to use to assess who I want to vote for. I don't think there will be a perfect match. CARE's campaign to 'Make the cross count' may help me decide, as might voteforpolicies.org.uk
Election coverage is all over the place, if you'd like to check out the parties' manifestos and positions on various issues, the BBC website looks comprehensive.
Without wishing to end on cynical note, Radiohead's 1997 take on the whole thing still rings true...