There are a wide range of options for wood treatments inside. Eco Home Centre recommend Osmo products for any untreated woods, but for pre-painted wood the choice of products is more complicated. For quick drying and VOC free painting, earthBorn ProAqua Eggshell is superb. For cheap and odour free painting, Green Paints are excellent (although we can only recommend their semi-gloss version), Auro's oil and water based paints are also good quality paints.
For certain jobs we would recommend certain products, so for door jambs we would suggest the earthBorn ProAqua as this is so quick drying, skirting boards we would suggest Green Paint and for areas that are likely to take knocks the Auro 250 has the oil content to make it harder wearing.
Osmo opaque finishes are given by the Wood Wax Creativ range with the transparent being the Wood Waxes. Wood Oils can also be used internally and the clear UV stable 410 is a great way of preserving natural colour in your wood.
Osmo Top Oil is excellent for wooden work surfaces and tables and their Door Oil for doors (oddly enough). See Flooring for the famous Osmo Polyx Oil. This can be used for any really hard wearing areas / objects.
If pretreatment is required (wood that is often splashed with water etc) use the Osmo Wood Protector 4006.