I Drove my car about 3 miles and when i got home i had noticed the front wheels smoking a little. Is this due to the brake pads wearing in as they are new and the old brake fluid burning off? Bit worried to drive it.
This is completely normal for most brakes right after installation. It's due to the paint on the pads as well as them breaking in. The brake pads get extremely hot during braking, which cures the binding agents in the friction material, causing a bit of smoke. This should only happen one time.
If there was brake fluid on your brake rotor or new pads, I'd suggest you have bigger problems. All of this should have been cleaned off prior to assembly. If you have left brake fluid on these parts, you may need to have them replaced due to contamination. Further still, where did the brake fluid come from? The braking system is considered sealed until you open something up or something fails and a leak occurs. You will not have any brake fluid present under normal circumstances when you change pads/rotors.
This could indicate that the pads are not releasing from the discs fully. Typically the brake pads rest in and slide over part of the caliper. When you replace the pad, the additional thickness can mean that the pad sits in an area which previously hadn't been used in a while. When changing brake components, it is advisable that all areas that "slide" are cleaned with a stiff wire brush, optionally emery paper and then lubricated with a suitable grease.
For traditional braking systems, I would advise copper-slip. However, on modern cars with ABS, ceratec grease is preferable as it won't interfere with electromagnetic sensors.
One word of caution, DO NOT TOUCH a brake disc that has been smoking until it has cooled down.
I'd suggest jacking the car up and making sure that the wheel spins freely. If it does, it's just the newness burning off. If not, pop the caliper off and clean and lubricate everything.