Welcome!
There have been previous political threads, like here, here, or here. If you search "politics," you'll find quite a bit. Here was my response to the proposal that we have political discussion threads; basically, I think politics is a suboptimal way to spend your time. It might feel useful, but that doesn't mean it is useful. Here's Raemon's comment on the norm against discussing politics. Explicitly political discussion can be found on MoreRight, founded by posters active on LessWrong, as well as on other blogs. (MoreRight is part of 'neoreaction', which Yvain has recently criticized here, for example.)
I don't see what you mean by the 'pros and cons' of holding a particular ideology. Ideologies are, generally, value systems- they define what is a pro and what is a con.
I must add that not all political discussion is a mud-flinging match between the Cyans and the Magentas.
For example, the Public Choice theory is a bona fide intellectual topic, but it's also clearly political.
I would also argue that knowing things like the scope of NSA surveillance is actually useful.
A few notes about the site mechanics
A few notes about the community
If English is not your first language, don't let that make you afraid to post or comment. You can get English help on Discussion- or Main-level posts by sending a PM to one of the following users (use the "send message" link on the upper right of their user page). Either put the text of the post in the PM, or just say that you'd like English help and you'll get a response with an email address.
* Normal_Anomaly
* Randaly
* shokwave
* Barry Cotter
A note for theists: you will find the Less Wrong community to be predominantly atheist, though not completely so, and most of us are genuinely respectful of religious people who keep the usual community norms. It's worth saying that we might think religion is off-topic in some places where you think it's on-topic, so be thoughtful about where and how you start explicitly talking about it; some of us are happy to talk about religion, some of us aren't interested. Bear in mind that many of us really, truly have given full consideration to theistic claims and found them to be false, so starting with the most common arguments is pretty likely just to annoy people. Anyhow, it's absolutely OK to mention that you're religious in your welcome post and to invite a discussion there.
A list of some posts that are pretty awesome
I recommend the major sequences to everybody, but I realize how daunting they look at first. So for purposes of immediate gratification, the following posts are particularly interesting/illuminating/provocative and don't require any previous reading:
More suggestions are welcome! Or just check out the top-rated posts from the history of Less Wrong. Most posts at +50 or more are well worth your time.
Welcome to Less Wrong, and we look forward to hearing from you throughout the site!
Note from orthonormal: MBlume and other contributors wrote the original version of this welcome post, and I've edited it a fair bit. If there's anything I should add or update on this post (especially broken links), please send me a private message—I may not notice a comment on the post. Finally, once this gets past 500 comments, anyone is welcome to copy and edit this intro to start the next welcome thread.