Advice Needed: Accept Paid Links?

[SweetPotato]

The interweb is full of people who claim to know the secrets of SEO.

Now, it would seem, those people are coming to me with increasing regularity to ask me if I would be happy to put paid links on my site (I think my Page Rank went up, hence the requests).

I've had 6 emails in the last 3 days saying something like:

I’m contacting you on behalf of my client in the legal sector that is wishing to heighten their online presence, via working with excellent websites such as yours. 

They are one of, if not the most respected practice in the UK and cover all legal verticals, including: medical negligence, accidents at work, family law and holiday claims amongst others.

I’ve approached you as I think your site would an ideal space for my client to sponsor a page or perhaps incorporate a link of some description.

I'm happy to take their money, frankly. However, some initial research suggests that Google could potentially penalise both my site and the site buying links if they deem their links to be paid. I think that pretty much the only way Google can tell if a link is paid is if it is "not natural" looking, i.e. nothing to do with my site content (not the case by the sound of most of the emails) or the anchor text is too obvious, eg the world's best law firm rather than Biggie & Smalls Solicitors LLP.

My question is, does anybody have experience dealing with SEOs on this type of thing? And what advice can you give in terms of how I should present the content and crucially the links?

Thanks

SP

ps. from my research, I now understand why Ning makes us use nofollow links.

[SweetPotato]

Thanks everybody for the advice and answers, very helpful
SP

[ismail shah]

i created a seprate page for all type of advertisers and i deal with them for link exchange only.

you can check my Link Exchange Page Here

i think link exchange boost SEO .