At £25NL (which is, both fiscally and in terms of ability, somewhere between $25NL and $50NL), I would say that someone calling your TPTK bet on the flop and then min-raising (or more) on the turn is a sign of two pair or better about 75% of the time, and without a read, I will usually fold, depending on pre-flop betting, table texture, outs etc.

At $25, it's more like a toss-up. The thing about noobs is they either a) only raise with strong hands or b) raise far too often, and if you know they're not type b), then you have to wonder what they could have and be prepared to lay it down.